Triacylglycerol Concentrations Research Articles

Monomethyl branched-chain fatty acids enriched bacterial oil production by furan aldehydes tolerant halophile Lentibacillus salarius strain BPIITR using non-detoxified sugarcane bagasse

The structural diversity of monomethyl branched-chain fatty acids (mBCFAs) expanded their application in biolubricants, biofuels for enhancing cold flow and thermo-oxidative properties. Current study focuses on mBCFAs production from sugarcane bagasse hydrolysate in biorefinery approach with halophilic Lentibacillus salarius BPIITR. Halophilic bacterium exhibited tolerance towards furan aldehydes up to 150 mM in minimal medium and produced 3.40 ± 0.13 and 2.47 ± 0.15 gL−1 lipid rich in mBCFAs, in xylose and glucose rich non-detoxified hydrolysate, respectively at bench-scale bioreactor. In addition, 2,5-furandicarboxylic acid and 2-furancarboxylic acids were co-produced as value-added products up to 41.34 ± 4.73 and 59.84 ± 5.17 mM, respectively. The biosynthesized bacterial oil exhibited onset oxidation temperature of 319.5 °C and low temperature viscosity ratio of 2.92. The accumulated lipid was rich in triacylglycerol content more than 67 % with 12-methyl tetradecanoic acid as major fatty acid.

Dietary Grape Seed Tannins Affect Lipoproteins, Lipoprotein Lipases and Tissue Lipids in Rats Fed Hypercholesterolemic Diets , ,

The effects of monomeric and polymeric grape seed tannins on rat plasma lipoproteins, lipoprotein lipase, hepatic lipase and aortic and hepatic lipid concentration were studied. Male Sprague-Dawley rats received either a normal diet (with no added cholesterol and no tannins), a control diet (hypercholesterolemic diet) or hypercholesterolemic diets supplemented with 2% tannin monomers or 2% polymers 3 or 9 wk. Plasma total cholesterol, triacylglycerol, LDL cholesterol and VLDL concentrations were significantly higher and the HDL cholesterol concentration lower in controls and in rats fed the diet supplemented with monomers compared with rats fed polymeric tannins at both time points. Lipoprotein lipase and hepatic lipase activities were significantly higher in control and in monomer-fed groups than in the polymer-fed group. Hepatic and aortic cholesterol and triacylglycerol concentrations were significantly higher in control rats and those fed monomers than in the polymer-fed group. Moreover, plasma HDL cholesterol and hepatic lipase activity were closely associated with low aortic cholesterol and triacylglycerol in rats fed polymeric tannins. These rats also exhibited greater fecal excretion of cholesterol and especially bile acids than the control or monomer-fed groups. Thus dietary grape seed tannins have a pronounced anti-hypercholesterolemic effect by enhancing reverse cholesterol transport and also by reducing intestinal cholesterol absorption and increasing bile acid excretion.

Resistant Starch Decreases Serum Total Cholesterol and Triacylglycerol Concentrations in Rats

Rats were meal-fed semipurified diets containing a low (0.8 g/MJ) and a high (9.6 g/MJ) amount of resistant starch (RS) or various amounts of RS (0.8 to 9.6 g/MJ) and guar gum (0 to 8.8 g/MJ). In one experiment, rats were fed the low and high RS diets in three dietary regimens (ad libitum consuming, 12 h ad libitum/12 h food deprived, and meal fed). Effects of RS and guar gum on serum postprandial and postabsorptive concentrations of total cholesterol (TC) and triacylglycerol (TAG), growth, hydrogen excretion, tissue weights and contents of small intestine and cecum, and pH of cecal contents were investigated. In addition, effects of RS on food intake, de novo hepatic synthesis of fatty acids and neutral sterols, and on lipoprotein lipase activity and weight of epididymal fat pads were investigated. Compared with feeding the low RS diet, the high RS diet reduced the serum TC and TAG concentrations, with these effects observed after 1 and 2 wk of feeding, respectively. The dietary regimen did not influence the effect of RS on the serum TC and TAG concentrations, but it did affect the serum TAG concentration. Resistant starch had no effect on the hepatic synthesis of fatty acids and neutral sterols or on the lipoprotein lipase activity in epididymal fat pads. Guar gum also reduced the serum TC concentration, but it had no effect on serum TAG concentration. The tissue weights and contents of small intestine and cecum as well as hydrogen excretion increased with increasing amounts of dietary RS and guar gum, whereas the pH of cecal contents decreased. No effects of RS on food intake and total body weight gain were found, whereas guar gum decreased weight gain. Feeding the high RS diet also led to a lower weight of the epididymal fat pads. We conclude that dietary RS can reduce serum TC and TAG concentrations and fat accretion.

Microalgal glycerol-3-phosphate acyltransferase role in galactolipids and high-value storage lipid biosynthesis.

Glycerolipids are the most abundant lipids in microalgae, and glycerol-3-phosphate:acyl-CoA acyltransferase (GPAT) plays an important role in their biosynthesis. However, the biochemical and biological functions of algal GPAT remain poorly characterized. Here, we characterized the endoplasmic reticulum (ER)-associated GPAT of the model unicellular green alga Chlamydomonas reinhardtii (CrGPATer). Enzymatic assays indicated that CrGPATer is an sn-1 acyltransferase using a variety of acyl-CoAs as the acyl donor. Subcellular localization revealed that CrGPATer was associated with ER membranes and lipid droplets. We constructed overexpression (OE) and knockdown (KD) transgenic C. reinhardtii lines to investigate the in vivo function of CrGPATer. Lipidomic analysis indicated that CrGPATer OE enhanced the cellular content of galactolipids, especially monogalactosyldiacylglycerol, under nitrogen deficiency stress. Correspondingly, CrGPATer KD lines contained lower contents of galactolipids than the control. Feeding experiments with labeled phosphatidic acid revealed that the intermediate of the eukaryotic Kennedy pathway could be used for galactolipid biosynthesis in the chloroplasts. These results provided multiple lines of evidence that the eukaryotic Kennedy pathway mediated by CrGPATer may be involved in galactolipid biosynthesis in C. reinhardtii. OE of CrGPATer significantly increased the content of triacylglycerol and the yield of biomass. Moreover, the content and yield of 1, 3-olein-2-palmitin, a high-value lipid that can be used as an alternative for human milk fat in infant formula, were significantly enhanced in the OE transgenic lines. Taken together, this study provided insights into the biochemical and biological functions of CrGPATer and its potential as a genetic engineering target in functional lipid manufacturing.

A compound of paraprobiotic and postbiotic derived from autochthonous microorganisms improved growth performance, epidermal mucus, liver and gut health and gut microbiota of common carp (Cyprinus carpio)

High-density intensive farming is the development trend of modern aquaculture, which is characterized by high density culture environment and feeding of high-fat diet. The use of high-fat diet can increase the weight gain rate of some fish species, but it affects the health of fish. In this study, we investigated the beneficial effects of a compound of paraprobiotic and postbiotic (CPP) derived from autochthonous microorganisms supplemented diet on growth performance, epidermal mucus, liver and gut health, and gut microbiota profile of common carp (Cyprinus carpio). Common carp were fed with diets supplemented with 0, 1, 2 or 3 g/kg of CPP in the control diet for 14 weeks, with four replications in each group and 20 fish in each repetition. The results showed that fish fed with diet supplemented with CPP significantly decreased the hepatosomatic index (p < 0.05), even though no significant effects were observed in the growth performance of the fish. In the CPP1.0 and CPP2.0 groups the level of complement 4 and superoxide dismutase (SOD) activity in the epidermal mucus were significantly increased compared to the control group (p < 0.05). No significant values were recorded among the treatment groups in the level of Lysozyme activity and total antioxidant capacity (T-AOC) (p > 0.05). For liver health, dietary CPP2.0 were significantly decreased the Triacylglycerol content in the liver, compared with the control (p < 0.05). Furthermore, fish groups fed with CPP1.0 and CPP2.0 showed significant decreased in the number of vacuoles representing lipid droplets and the liver damage scores (p < 0.05), compared with the control group. The CPP2.0 group significantly decreased serum alanine aminotransferase (Alt) and aspartate aminotransferase (Ast) levels, and significantly increased liver antioxidant (total antioxidant capacity, superoxide dismutase and catalase (CAT)) levels compared to the control group (p < 0.05). The level of liver malondialdehyde (MDA) was significantly reduced in the CPP groups compared to the control (p < 0.05). Dietary CPP supplementation were significantly down-regulated the relative expression of pro-inflammatory cytokines (nf-κb p65 and tnf-α) and up-regulated anti-inflammatory cytokines (il-1β, il-10 and tgf-β), compared to the control group (p < 0.05). Similarly, intestinal hypoxia inducible factor 1 subunit alpha (hif-1α) expression was significantly increased in the CPP1.0 and 2.0 groups, compared with then control (p < 0.05). Combined with intestinal HE staining and inflammatory gene expression, it was found that the intestinal inflammatory cytokines (nf-κb p65, il-1β, il-10 and tgf-β) in the CPP2.0 supplemented group were significantly higher than the control group (p < 0.05), and the intestinal villi were more orderly arranged. In the CPP3.0 group, the expression of nf-κb p65, il-1β, il-10 were significantly higher compared with the control (p < 0.05). Furthermore, remarkably lower intestinal injury scores were recorded in the CPP groups verses the control (p < 0.05). The gut microbiota diversity index data showed that lower diversity index values were observed in the CPP2.0 group compared with the control (p < 0.05). The relative abundances of Fusobacteria and Cetobacterium in the CPP2.0 and 3.0 groups were significantly higher than those in the control group (p < 0.05). In conclusion, dietary CPP supplementation could enhance non-specific immunity and antioxidant levels, reduce liver lipid deposition, alleviate liver and intestinal damage and inflammation, and improve gut microbiota abundance and diversity in common carp fed with high-fat diet. The best positive effect was observed in common carp fed with diet supplemented at a level of 2 g/kg of basal diet.

Application evaluation of linseed oil as a substitute for fish oil in the commercial diet for juvenile Portunus trituberculatus

Vegetable oil (VO) is increasingly replacing fish oil (FO) in the commercial diet of crustaceans, partly due to a global shortage of FO. But little is known about how different amounts of substitution affect the health and metabolism of crustaceans. A six-week feeding trial was conducted to evaluated the effects of different replacement levels of FO with linseed oil (LO) on growth performance, antioxidant and digestive capacity and fatty acid metabolism in swimming crab, Portunus trituberculatus. Five isonitrogenous and isolipidic diets (480 g kg−1 protein and 120 g kg−1 lipid) were formulated to contain graded levels of LO, and FO was replaced with LO at 0%, 25%, 50%, 75% and 100%, respectively. The results showed that 50% of FO could be replaced by LO without affecting the growth performance and feed utilization for juvenile swimming crab. In hemolymph, 100% dietary replacement of FO with LO, the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) exhibited significantly higher than those fed the other diets, the concentrations of triacylglycerol (TAG), total cholesterol (T-CHO) and high-density lipoprotein cholesterol (HDL-C) significantly increased with increase of dietary replacement of FO with LO, which may lead to hyperlipidemia in swimming crabs. The number of R cells and their lipid droplets in hepatopancreas gradually increased with increase of replacement of FO with LO, the results confirmed the occurrence of lipid accumulation in the hepatopancreas. The activities of glutathione (GSH), and glutathione peroxidase (GPX) in hepatopancreas significantly decreased with increase of replacement of FO with LO, and crabs fed diet with 50% replacement of FO with LO had higher activities of trypsin and lipase (LPS) than those fed the other diets. Long-chain polyunsaturated fatty acids (LC-PUFA), n-3/n-6 PUFA in hepatopancreas and muscle significantly decreased with the increase of substitution level of FO with LO. Moreover, the expression of genes related to LC-PUFA synthesis as well as fatty acid β-oxidation, such as elongase 4 (elovl4), hepatocyte nuclear factor 4-α (hnf4α), retinoid X receptor (rxr), carnitine palmitoyltransferase 2 (cpt2) and acyl-CoA oxidase (acox2), were down-regulated with increase of dietary replacement of FO with LO. In conclusion, it is suggested that the optimal substitution ratio of LO for FO should be less than 50% in the diet of Portunus trituberculatus.

A lipid droplet-associated protein Nem1 regulates appressorium function for infection of Magnaporthe oryzae

Lipid droplets are important storages in fungal conidia and can be used by plant pathogenic fungi for infection. However, the regulatory mechanism of lipid droplets formation and the utilization during fungal development and infection are largely unknown. Here, in Magnaporthe oryzae, we identified a lipid droplet-associated protein Nem1 that played a key role in lipid droplets biogenesis and utilization. Nem1 was highly expressed in conidia, but lowly expressed in appressoria, and its encoded protein was localized to lipid droplets. Deletion of NEM1 resulted in reduced numbers of lipid droplets and decreased content of diacylglycerol (DAG) or triacylglycerol (TAG). NEM1 was required for asexual development especially conidia production. The Δnem1 mutant was nearly loss of virulence to host plants due to defects in appressorial penetration and invasive growth. Remarkably, Nem1 was regulated by the TOR signaling pathway and involved in the autophagy process. The Ser303 residue of Nem1 could be phosphorylated by the cAMP-PKA signaling pathway and was important for biological function of Nem1. Together, our study revealed a regulatory mechanism of lipid biogenesis and metabolism during the conidium and appressorium formation of the rice blast fungus.

The antioxidant effect of chitosan on virgin and mated Drosophila females

Mating causes decreased life span and oxidative damage in female Drosophila. We investigated the effect of under mating and virginity oxidative stress-induced damage and soluble Chitosan (Ch) supplementation. It was determined as antioxidant capacity (TAS) and total oxidation (TOS), triacylglycerol (TAG), protein and glycogen concentration of Ch (1–20 mg/mL) on young-old mated and virgin flies (Drosophila melanogaster). We were found that females of mating and aging groups feeding with Ch were lower levels of stress. Feeding with high concentrations of Ch in aging decreased the amount of TAG and glycogen, while increasing the amount of protein. The study suggests that higher antioxidant defenses in virgin and old females confer resistance to oxidative stress, because of feeding with 20% Ch. Data shows that mating status affects fly physiology and metabolism in free radical processes.

Influence of Flavonoid-Rich Fraction of Monodora tenuifolia Seed Extract on Blood Biochemical Parameters in Streptozotocin-Induced Diabetes Mellitus in Male Wistar Rats.

Diabetes mellitus is a metabolic disorder caused by either the total destruction of the pancreatic beta cells that secrete insulin for the uptake of glucose from the circulation or as a result of the inability of body cells to respond to the presence of insulin in the blood. The present study investigated the effect of a flavonoid-rich fraction of Monodora tenuifolia seed extract (FFMTSE) on blood parameters in streptozotocin (STZ)-induced diabetic male Wistar rats. The rats were divided into seven groups (n = 6). Group 1: normal control rats, Group 2: rats + FFMTSE (25 mg/kgbwt), Group 3: rats + FFMTSE (50 mg/kgbwt), Group 4: diabetic control rats, Group 5: diabetic rats + FFMTSE (25 mg/kgbwt), Group 6: diabetic rats + FFMTSE (50 mg/kgbwt), and Group 7: diabetic rats + Metformin. The assessment of the lipid profile, kidney functions (urea and creatinine), and cardiac biomarkers (LDH and CK-MB) were carried out in the plasma using established protocols. The results showed a significant increase in the concentrations of triacylglycerol, cholesterol, LDL-cholesterol, VLDL-cholesterol, urea, and creatinine, as well as in cardiac enzyme activities in diabetic rats. However, the administration of the FFMTSE significantly improved the observed biochemical parameters. In addition, an increased concentration of HDL-cholesterol concentration was observed in the diabetic rats upon treatment with FFMTSE. These findings indicate that FFMTSE could be a potent anti-nephropathy and anti-cardiomyopathy agent in diabetic conditions.

Lipid Profile of the Freshwater Pearl Mussel Margaritifera margaritifera Inhabiting Different Biotopes of the Lake-River System of the Kem River, White Sea Basin

The freshwater pearl mussel Margaritifera margaritifera is considered to be the most rapidly declining species of freshwater bivalve, whereas its colonies in rivers of the White Sea Basin remain the most numerous in the world. The lipid profiles of mantle, muscle (foot), and digestive gland tissues of the freshwater pearl mussel from the Kem, Ukhta, and Vozhma Rivers in autumn (end of September, early October) were studied using high performance thin-layer chromatography. The highest total lipid [TL] content was found in the digestive gland. Cholesterol esters, non-esterified fatty acids, phospholipids, and cholesterol were the dominant lipids in all studied tissues. The reduced triacylglycerol content in the mussels was associated with its utilization during the spawning period. The colony of the freshwater pearl mussel inhabiting the Vozhma River was distinguished by higher TL content in the mantle and digestive gland. Data on the size-age characteristics of mollusks from the Kem, Ukhta, and Vozhma Rivers and the relationship between the structural and storage lipid content and size-age parameters are discussed. The results are important for different conservation strategies of endangered species, such as the freshwater pearl mussel, especially in ecological monitoring based on evaluation of the physiological and biochemical state of mollusks and rare natural colonies.

Overexpressing an Arabidopsis SEIPIN1 reduces rubber particle size in guayule

A conventional source of natural rubber (NR) is from Hevea (Hevea brasiliensis). NR production from Hevea is limited by its narrow growth region and susceptibility to leaf blight disease. In response to these limitations, and to address NR supply and security, guayule (Parthenium argentatum Gray) has been developed as an alternative crop. NR consists mainly of cis-1,4-polyisoprene synthesized in/on rubber particles (RPs). RPs resemble lipid droplets (LDs) in that both are generated from endoplasmic reticulum (ER) and consist of hydrophobic cores and phospholipid monolayers. A prominent ER-related protein seipin plays an essential role in controlling LD biogenesis from the ER surface. Prior expression of AtSEIPIN1 in Arabidopsis increased LD size and consequently increased its core constituent triacylglycerol content in seed. To investigate if AtSEIPIN1 can similarly impact RPs and production of cis-1,4-polyisoprene, we generated three independent transgenic guayule lines overexpressing AtSEIPIN1 (SEIoe). Compared with wild-type, fewer RPs were observed, and RP size was significantly reduced in all SEIoe lines. Although not always statistically significant, NR quantity and quality were also reduced in SEIoe lines. Resin contents were reduced in mature stems, but not in young plantlets of SEIoe lines. The mechanisms of how AtSEIPIN1 influences RP biogenesis and NR production in guayule are discussed.

Circadian rhythm parameters and physical activity associated with cardiometabolic risk factors in the PREVIEW lifestyle study

The aim of this study was an assessment of post hoc associations among circadian rhythm parameters, physical activity (PA), and cardiometabolic risk factors in adults with obesity and prediabetes after 3 years of weight loss maintenance. Circadian rhythm parameters (continuous wrist-temperature measurements), PA, systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), plasma high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, remnant cholesterol, triacylglycerol, and C-reactive protein (CRP) concentrations were determined in 91 free-living participants (mean [SD], age=56.6 [10] years; BMI =28.2 [4.0]; homeostatic model assessment of insulin resistance [HOMA-IR]=3.2 [3.1]) and in 38 participants in sedentary respiration chamber conditions (age=56.6[10] years; BMI=28.5[4.0]; HOMA-IR=3.3 [1.4]). Associations of circadian rhythm parameters and PA with cardiometabolic risk factors were determined using factor analyses followed by Pearson correlations. Values of cardiometabolic risk factors were similar, whereas circadian rhythm parameters and PA differed significantly (p < 0.05) between conditions. In both conditions, parameters indicating a robust circadian rhythm associated inversely with CRP and positively with plasma HDL-C concentrations. In free-living conditions, PA associated inversely with SBP and HR and positively with HDL-C and robust circadian rhythm parameters. In sedentary conditions, PA associated positively with HR and inversely with robust circadian rhythm parameters. PA mediated the inverse association of parameters indicating a robust circadian rhythm with SBP in free-living conditions. In adults with obesity and prediabetes, parameters indicating a robust circadian rhythm were, independently of PA, associated with lower cardiometabolic risk and CRP. Only in free-living conditions, PA mediated the association of higher circadian stability with lower SBP.

Dietary (n-3) Polyunsaturated Fatty Acids Improve Adipocyte Insulin Action and Glucose Metabolism in Insulin-Resistant Rats: Relation to Membrane Fatty Acids

To study the effects of dietary fish oil on insulin-stimulated glucose metabolism in adipocytes of insulin-resistant rats (rats fed 50% sucrose and 30% fat), eighteen 5-wk-old Sprague-Dawley rats were fed, for 6 wk, a diet containing 30% fat as either fish oil (FO) or a mixture of vegetable and animal oils [control oils (CO)]. A third reference group was fed a standard diet (62% corn starch and 13% fat). At the end of the 6-wk period, the two experimental groups had comparable plasma glucose concentrations that were higher than that found in the reference group. FO feeding corrected the hyperinsulinemia of the experimental rats (P < 0.05) to reach values in the reference group. Plasma triacylglycerol (P < 0.01) and cholesterol (P < 0.001) concentrations were also lower in rats fed FO than in those fed CO. The body weights of FO-fed rats were similar to that of CO-fed rats, but epididymal adipose tissue weight was lower (P < 0.01). Adipocytes of FO-fed rats, compared with those of CO-fed rats, had high insulin-stimulated glucose transport (P < 0.05), oxidation (P < 0.001) and incorporation into total lipids (P < 0.05). The incorporation of (n-3) polyunsaturated fatty acids in adipocyte membrane phospholipids was higher in FO-fed rats than in those fed CO (P < 0.0001). Insulin action was positively correlated with the fatty acid unsaturation index in membrane phospholipids. Thus dietary fish oil has beneficial effects on insulinemia, plasma lipids and insulin-stimulated glucose metabolism in insulin-resistant slightly diabetic rats.

Growth and fatty acid distribution over lipid classes in Nannochloropsis oceanica acclimated to different temperatures.

After light, temperature is the most relevant environmental parameter in outdoors cultivation of microalgae. Suboptimal and supraoptimal temperatures negatively impact growth and photosynthetic performance with a subsequent effect on lipid accumulation. It is generally recognised that lower temperatures trigger an increase in fatty acid desaturation while higher temperatures trigger the opposite reaction. The effect of temperature on lipid classes has been less studied in microalgae and in certain cases, the effect of light cannot be completely excluded. In this research, the effect of temperature on growth, photosynthesis, and lipid class accumulation in Nannochloropsis oceanica was studied at a fixed light gradient with a constant incident light intensity (670 μmol m-2 s-1). A turbidostat approach was used to achieve temperature acclimated cultures of Nannochloropsis oceanica. Optimal growth was found at 25-29°C, while growth was completely arrested at temperatures higher than 31°C and lower than 9°C. Acclimation to low temperatures triggered a decrease in absorption cross section and photosynthesis rates with a tipping point at 17°C. Reduced light absorption was correlated with a decrease in content of the plastid lipids monogalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol. The increase of diacylglyceryltrimethylhomo-serine content at lower temperatures indicated a relevant role of this lipid class in temperature tolerance. Triacylglycerol content increased at 17°C and decreased at 9°C emphasising a metabolic switch in stress response. Total and polar eicosapentaenoic acid content remained constant at 3.5 and 2.4% w/w, despite the fluctuating lipid contents. Results show an extensive mobilisation of eicosapentaenoic acid between polar lipids classes at 9°C to ensure cell survival under critical conditions.

Increased Expression of Hepatic Stearoyl-CoA Desaturase (SCD)-1 and Depletion of Eicosapentaenoic Acid (EPA) Content following Cytotoxic Cancer Therapy Are Reversed by Dietary Fish Oil.

Cancer treatment evokes impediments to liver metabolism that culminate in fatty liver. This study determined hepatic fatty acid composition and expression of genes and mediators involved in lipid metabolism following chemotherapy treatment. Female rats bearing the Ward colon tumor were administered Irinotecan (CPT-11) +5-fluorouracil (5-FU) and maintained on a control diet or a diet containing eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) (2.3 g/100 g fish oil). Healthy animals provided with a control diet served as a reference group. Livers were collected one week after chemotherapy. Triacylglycerol (TG), phospholipid (PL), ten lipid metabolism genes, leptin, and IL-4 were measured. Chemotherapy increased TG content and reduced EPA content in the liver. Expression of SCD1 was upregulated by chemotherapy, while dietary fish oil downregulated its expression. Dietary fish oil down-regulated expression of the fatty acid synthesis gene FASN, while restoring the long chain fatty acid converting genes FADS2 and ELOVL2, and genes involved in mitochondrial β-oxidation (CPT1α) and lipid transport (MTTP1), to values similar to reference animals. Neither leptin nor IL-4 were affected by chemotherapy or diet. Depletion of EPA is associated with pathways evoking enhanced TG accumulation in the liver. Restoring EPA through diet may pose a dietary strategy to attenuate chemotherapy-associated impediments in liver fatty acid metabolism.

Propanol and 1, 3-propanediol enhance fatty acid accumulation synergistically in Schizochytrium ATCC 20888.

The effects of propanol and 1, 3-propanediol on fatty acid and biomass accumulation in Schizochytrium ATCC 20888 were explored. Propanol increased the contents of saturated fatty acids and total fatty acids by 55.4 and15.3%, while 1, 3-propanediol elevated the polyunsaturated fatty acids, total fatty acids and biomass contents by 30.7, 17.0, and 6.89%. Although both of them quench ROS to increase fatty acids biosynthesis, the mechanisms are different. The effect of propanol did not reflect on metabolic level while 1, 3-propanediol elevated osmoregulators contents and activated triacylglycerol biosynthetic pathway. The triacylglycerol content and the ratio of polyunsaturated fatty acids to saturated fatty acids were significantly increased by 2.53-fold, which explained the higher PUFA accumulation in Schizochytrium after adding 1, 3- propanediol. At last, the combination of propanol and 1, 3-propanediol further elevated total fatty acids by approximately 1.2-fold without compromising cell growth. These findings are valuable for scale-up production of designed Schizochytrium oil for various application purposes.

Applications of Diacylglycerol Acyltransferase for Triacylglycerol Production in Mortierella alpina.

Triacylglycerol (TG) with high-value long-chain polyunsaturated fatty acids is beneficial to human health; consequently, there is an urgent need to broaden its sources due to the current growing demand. Mortierella alpina, one of the most representative oleaginous fungi, is the only certificated source of dietary arachidonic acid-rich oil supplied in infant formula. This study was conducted to improve TG production in M. alpina by homologous overexpression of diacylglycerol acyltransferase (DGAT) and linseed oil (LSO) supplementation. Our results showed that the homologous overexpression of MaDGAT1B and MaDGAT2A strengthened TG biosynthesis and significantly increased the TG content compared to the wild-type by 12.24% and 14.63%, respectively. The supplementation with an LSO concentration of 0.5 g/L elevated the TG content to 83.74% and total lipid yield to 4.26 ± 0.38 g/L in the M. alpina-MaDGAT2A overexpression strain. Our findings provide an effective strategy for enhancing TG production and highlight the role of DGAT in TG biosynthesis in M. alpina.

Accurate quantification of TAGs to identify adulteration of edible oils by ultra-high performance liquid chromatography-quadrupole-time of flight-tandem mass spectrometry

Edible oils play important roles in biological functions, and triacylglycerols (TAGs) in edible oils are complex mixtures. This makes accurate TAGs quantitation quite difficult that bring economically motivated food adulteration. Herein, we demonstrated a strategy for accurate quantification of TAGs in edible oils, which could be applied in identification of olive oil adulteration. The results showed that the proposed strategy could significantly improve the accuracy of TAG content determination, reduce the relative error of fatty acids (FAs) content determination, and present a wider accurate quantitative range than that of gas chromatography-flame ionization detection. Most important, this strategy coupled with principal component analysis could be used to identify adulteration of high-priced olive oil with cheaper soybean oils, rapeseed oils or camellia oils at a lower concentration of 2%. These findings indicated that the proposed strategy could be regarded as a potential method for edible oils quality and authenticity analysis.

Changes in the content of pollen total lipid and TAG in Arabidopsis thaliana DGAT1 mutant as11.

In mature pollen grains, lipids are primarily stored in the form of lipid droplets that provide energy and act as a carbon source for normal pollen development and germination. Triacylglycerol (TAG) is the major form of stored plant lipids. Diacylglycerol transferase, which is encoded by DGAT1 in Arabidopsis thaliana, is an important enzyme regulating triacylglycerol synthesis. Within the seeds of the DGAT1 mutant as11, the content of TAG is significantly decreased and the fatty acid composition also differs from the wild type. Transcriptome data of mature anthers showed that the genes involved in the TAG synthesis pathway were downregulated in as11. Analysis of gene expression patterns via transcriptome data also revealed that the expression of PDAT1, which functions in a manner complementary to the DGAT1 gene, was significantly decreased in as11, whereas the amylopectin synthase genes SS1 and SS2 were upregulated in mutant as11. We also detected lower total lipid, TAG and fatty acid contents in mature as11 pollen, with palmitic acid (C16:0) and linolenic acid (C18:3) being the major fatty acids in mature pollen. The cytological results showed that the lipid droplet content was reduced in mature as11 pollen. In the binuclear pollen grain II stage, WT pollen contained lipid droplets that were primarily accumulated around the generative nucleus, whereas the pollen in the mutant as11 was rich in starch grains that were primarily distributed around the vegetative nucleus. Ultrastructural analysis indicated that during pollen development in as11, the amount of endoplasmic reticulum in tapetal cells and pollen grains decreased, whereas the Golgi body content increased, which directly or indirectly led to a decrease in the levels of lipidosomes and an increase in the starch content in as11. Changes in the lipid content and fatty acid composition of the mutant as11 differ from those in the wild type during pollen development.

Severe gestational diabetes mellitus in lean dams is associated with low IL-1α levels and affects the growth of the juvenile mouse offspring

We investigated how maternal gestational diabetes (GDM) impacts the metabolic status of offspring. GDM was induced in CD1 mice consuming a fast-food diet (FFD) by repeated low-dose streptozotocin injections before mating. Offspring of normoglycemic standard chow or the FFD consuming dams served as controls. In 4-week-old offspring weaned to standard chow, plasma concentrations of extracellular DNA, inflammatory markers, and parameters of the cardiometabolic status (glycemia, liver lipid content; body, organ, and fat weight) were determined. Two-factor analysis of variance indicated that the male offspring of GDM dams manifest postnatal growth retardation and lower relative kidney weight. Regardless of sex, GDM offspring manifest the lowest IL-1α levels, and other inflammatory markers showed mild and inconsistent alterations. Offspring of dams consuming the FFD displayed higher liver triacylglycerols content. The three groups of offspring showed no significant differences in glycemia and extracellular DNA. Partial least squares-discriminant analysis indicated that male GDM offspring present lower kidney, body, and brown adipose tissue weights; lower IL-1α levels, and higher concentrations of GM-CSF and IL-10 compared with their FFD counterparts. The model failed to select discriminative variables in females. In conclusion, in mice, maternal GDM in the absence of obesity adversely affects the early growth of juvenile male offspring.