Triacylglycerol Concentrations Research Articles

β-sitosterol Alleviates High Fatty Acid-Induced Lipid Accumulation in Calf Hepatocytes by Regulating Cholesterol Metabolism

A significant reduction in plasma concentration of cholesterol during early lactation is a common occurrence in high-yielding dairy cows. An insufficient synthesis of cholesterol in the liver has been linked to lipid accumulation caused by high concentrations of fatty acids during negative energy balance (NEB). As ruminant diets do not provide quantitative amounts of cholesterol for absorption, phytosterols such as β-sitosterol may serve to mitigate the shortfall in cholesterol within the liver during NEB. To gain mechanistic insights, primary hepatocytes were isolated from healthy female 1-day old calves for in vitro studies with or without 1.2mM fatty acids (FA) to induce metabolic stress. Furthermore, hepatocytes were treated with 50μM β-sitosterol with or without FA. Data were analyzed by one-way ANOVA with subsequent Bonferroni correction. Results revealed that calf hepatocytes treated with FA had greater content of non-esterified fatty acids (NEFA) and triacylglycerol (TAG), and greater mRNA and protein abundance of the lipid synthesis-related SREBF1 and FASN. In contrast, mRNA and protein of CPT1A (fatty acid oxidation) and the cholesterol metabolism-related targets SREBF2, HMGCR, ACAT2, APOA1, ABCA1 and ABCG5 was lower. Content of the antioxidant-related glutathione (GSH) and activities of superoxide dismutase (SOD) also was lower. Compared with FA challenge alone, 50μM β-sitosterol led to greater mRNA and protein abundance of SREBF2, HMGCR, ACAT2 and ABCG5, and greater content of GSH and activity of SOD. In contrast, compared with the FA group, the mRNA and protein abundance of SREBF1 and ACC1 and the content of TAG and NEFA in the β-sitosterol + FA group were lower. Overall, β-sitosterol can promote cholesterol metabolism and reduce oxidative stress while reducing lipid accumulation in hepatocytes challenged with high concentrations of fatty acids.

Up-regulation of long non-coding RNA H19 ameliorates renal tubulointerstitial fibrosis by reducing lipid deposition and inflammatory response through regulation of the microRNA-130a-3p/long-chain acyl-CoA synthetase 1 axis

Long non-coding RNA (lncRNA) H19 is an extensively studied lncRNA that is related to numerous pathological changes. Our previous findings have documented that serum lncRNA H19 levels are decreased in patients with chronic kidney disorder and lncRNA H19 reduction is closely correlated with renal tubulointerstitial fibrosis, an essential step in developing end-stage kidney disease. Nonetheless, the precise function and mechanism of lncRNA H19 in renal tubulointerstitial fibrosis are not fully comprehended. The present work utilized a mouse model of unilateral ureteral obstruction (UUO) and transforming growth factor-β1 (TGF-β1)-stimulated HK-2 cells to investigate the possible role and mechanism of lncRNA H19 in renal tubulointerstitial fibrosis were investigated. Levels of lncRNA H19 decreased in kidneys of mice with UUO and HK-2 cells stimulated with TGF-β1. Up-regulation of lncRNA H19 in mouse kidneys remarkably relieved kidney injury, fibrosis and inflammation triggered by UUO. Moreover, the increase of lncRNA H19 in HK-2 cells reduced epithelial-to-mesenchymal transition (EMT) induced by TGF-β1. Notably, up-regulation of lncRNA H19 reduced lipid accumulation and triacylglycerol content in kidneys of mice with UUO and TGF-β1-stimulated HK-2 cells, accompanied by the up-regulation of long-chain acyl-CoA synthetase 1 (ACSL1). lncRNA H19 was identified as a sponge of microRNA-130a-3p, through which lncRNA H19 modulates the expression of ACSL1. The overexpression of microRNA-130a-3p reversed the lncRNA H19-induced increases in the expression of ACSL1. The suppressive effects of lncRNA H19 overexpression on the EMT, inflammation and lipid accumulation in HK-2 cells were diminished by ACSL1 silencing or microRNA-130a-3p overexpression. Overall, the findings showed that lncRNA H19 ameliorated renal tubulointerstitial fibrosis by reducing lipid deposition via modulation of the microRNA-130a-3p/ACSL1 axis.

Lipid changes and volatile compounds formation in different processing stages of dry-cured Spanish mackerel

Abstract This study delves into the alterations in lipids and major flavor compounds occurring throughout various drying stages (raw fish, dry-cured for 4 d, 8 d, and 12 d) of dry-cured Spanish mackerel (DCSM) and elucidates the mechanism behind their formation. The findings exhibit a notable reduction in phospholipid (PL), triacylglycerol (TAG), heptanal, t-2-hexenal, and dimethyl disulfide contents in the samples observed four days before processing. The peroxide value (POV) and thiobarbituric acid reactive substances (TBARS) witnessed a significant surge after 4-8 days, concomitant with the generation of numerous volatile compounds, encompassing alcohols, aldehydes, and ketones. Substantial quantities of 2-methylbutyraldehyde, thiazole, butyl acetate, and trimethylpyrazine emerged during the 8-12 days processing phase. Furthermore, C18:1n-9, C20:5n-3, and C22:6n-3 demonstrated noteworthy correlations with the development of 21 compounds. Principal Component Analysis (PCA), grounded in lipid and volatile compound content, adeptly classified the DCSM drying process into lipolysis and flavor preparation (0-4 d), lipid oxidation and flavor formation (4-8 d), and maturation (8-12 d). The ripening stage played a crucial role in shaping the comprehensive flavor profile. This study offers valuable insights to enhance the traditional DCSM flavor processing and regulation.

Lipidomic and transcriptomic analysis of triacylglycerol accumulation mechanism of pecan (Carya illinoinensis) nut

Pecan (Carya illinoinensis) holds significant prominence as an oil-seed nut, characterized by its high content of fatty acids and triacylglycerol (TG). The inclusion of TG in the C. illinoinensis nut is of paramount importance, not only contributing significantly to the nutritional value for human consumption but also serving as a reliable and eco-friendly resource for various industrial uses. The present study conducted a comprehensive analysis involving transcriptomics, lipidomics, and physiological assessments to explore the dynamic patterns and components of triacylglycerols (TG) in C. illinoinensis nuts throughout the ripening phase. Additionally, the investigation aimed to elucidate the molecular mechanisms governing TG metabolism. The physiological investigation conducted on the maturation progression of three cultivars of C. illinoinensis unveiled distinctive traits within each variety. Notably, ‘Mahan’ displayed elevated concentrations of oil and crude fat, in contrast to the contrasting trend observed in ‘Y-01’. Further lipidomic scrutiny exposed that ‘Mahan’ exhibited augmented levels of glycerides, specifically triglycerides (TG), monoacylglycerol (MG), and diacylglycerol (DG), compared to its counterparts during the ripening phase. The comparative analysis of RNA-Seq libraries uncovered a notable increase in unigenes associated with the ‘glycerolipid metabolism’ pathway. Moreover, the amalgamation of transcriptomic and lipidomic information indicated a heightened expression of genes implicated in TG metabolism in ‘Mahan’. Moreover, there was a strong association between CiGPAT3, CiDGAT1, CiTAGL2, and CiMAGL1 genes and TG metabolism during the ripening process of C. illinoinensis nuts. Utilizing weighted gene co-expression network analysis (WGCNA) identified six distinct modules linked to various ripening stages, alongside the discovery of ten transcription factor families implicated in regulating TG metabolism. In summary, our research provides significant insights into the molecular framework that governs the accumulation mechanism of triglycerides (TG) in C. illinoinensis nuts throughout the ripening phase, which plays a pivotal role in optimizing the yield of C. illinoinensis oil and fostering progress in the molecular breeding.

High Starch Induces Hematological Variations, Metabolic Changes, Oxidative Stress, Inflammatory Responses, and Histopathological Lesions in Largemouth Bass (Micropterus salmoides).

This study evaluated effects of high starch (20%) on hematological variations, glucose and lipid metabolism, antioxidant ability, inflammatory responses, and histopathological lesions in largemouth bass. Results showed hepatic crude lipid and triacylglycerol (TAG) contents were notably increased in fish fed high starch. High starch could increase counts of neutrophils, lymphocytes, monocytes, eosinophils, and basophils and serum contents of TAG, TBA, BUN, and LEP (p < 0.05). There were increasing trends in levels of GLUT2, glycolysis, gluconeogenesis, and LDH in fish fed high starch through the AKT/PI3K signal pathway. Meanwhile, high starch not only triggered TAG and cholesterol synthesis, but mediated cholesterol accumulation by reducing ABCG5, ABCG8, and NPC1L1. Significant increases in lipid droplets and vacuolization were also shown in hepatocytes of D3-D7 groups fed high starch. In addition, high starch could decrease levels of mitochondrial Trx2, TrxR2, and Prx3, while increasing ROS contents. Moreover, high starch could notably increase amounts of inflammatory factors (IL-1β, TNF-α, etc.) by activating NLRP3 inflammasome key molecules (GSDME, caspase 1, etc.). In conclusion, high starch could not only induce metabolic disorders via gluconeogenesis and accumulation of glycogen, TAG, and cholesterol, but could disturb redox homeostasis and cause inflammatory responses by activating the NLRP3 inflammasome in largemouth bass.

Multiple transcription factors of Arabidopsis thaliana that are activated by LEAFY COTYLEDON 2 regulate triacylglycerol biosynthesis.

Plant triacylglycerols (TAG) are used in food and various industrial feedstocks. LEAFY COTYLEDON 2 (LEC2), a master positive regulator of TAG biosynthesis, regulates a complex network of transcription factors (TFs) during seed development. Aside from WRINKLED1 (WRI1), the TFs regulated by LEC2 related to TAG biosynthesis have not yet been identified. Previously, we identified 25 seed-expressing TFs that were upregulated in Arabidopsis leaves that overexpressed senescence-induced LEC2. In this study, each of the 25 TFs was transiently expressed in the leaves of Nicotiana benthamiana to identify unknown TFs that regulate TAG biosynthesis. The TAG content of the transformed leaves was analyzed using thin layer chromatography and gas chromatography. We observed that five TFs, ARABIDOPSIS RESPONSIVE REGULATOR 21 (ARR21), AINTEGUMENTA-LIKE 6 (AIL6), APETALA2/ETHYLENE RESPONSIVE FACTOR 55 (ERF55), WRKY DNA-BINDING PROTEIN 8 (WRKY8), and ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN 38 (ANAC038) increased TAG synthesis in the leaves. Among these, the promoters of AIL6, ERF55, WRKY8, and ANAC038 contain RY motifs, which are LEC2-binding sites activated by LEC2. AIL6 overexpression in Arabidopsis increased the total fatty acid (FA) content in seeds and altered the FA composition, with increases in 16:0, 18:1, and 18:2 and decreases in 18:0, 18:3, and 20:1 compared with those in the wild type (WT). AIL6 overexpression activates several FA and TAG biosynthesis genes. Therefore, our study successfully identified several new TFs regulated by LEC2 in TAG biosynthesis and showed that AIL6 increased the TAG content in seeds.

Functional triacylglycerols from microalgae and their use in the formulation of functional foods—Review

Consumers increased demand for food products that promote health has compelled the food processing industry to develop food products that not only satiate hunger but also aid in the prevention of non-communicable diseases. Microalgae have emerged as a potential source of functional components like triacylglycerols containing essential fatty acids that could be used in the formulation of functional food products. These components help prevent non-communicable diseases due to their inherent characteristics like anti-oxidative, anti-cancer, anti-diabetic, anti-inflammatory, etc. The microalgae are concentrated sources of triacylglycerols containing essential fatty acids and are considered a potential replacer for fish oil in providing these functional ingredients also well accepted by the vegan. This review aims to cover the literature on the triacylglycerol content of microalgae with a focus on the functional triacylglycerol, the fatty acid composition of triacylglycerol extracted from different microalgal biomass, innovative extraction technologies for intensified extraction, the potential use of triacylglycerols from microalgae in the formulation of functional food products. Further, the present constraints and future prospectus in using microalgal triacylglycerol in functional food are also discussed.

Heterologous phospholipid:diacylglycerol acyltransferase channels eicosapentaenoic acid to triacylglycerol in Phaeodactylum tricornutum

Phaeodactylum tricornutum is a well-studied oleaginous model diatom with high triacylglycerol (TAG) and omega-3 eicosapentaenoic acid (EPA) contents, however, only a small portion of EPA is transferred from the polar lipids to TAG through phospholipid:diacylglycerol acyltransferase (PDAT). In this study, a Nannochloropsis oceanica PDAT (NoPDAT) was heterologously expressed in P. tricornutum to increase the EPA content in TAG. NoPDAT heterologous expression slightly disturbed the growth of the transgenic lines, but enhanced the TAG content by 16–18 %. Considering the localization of NoPDAT in P. tricornutum after heterologous expression together with our lipidomic results, NoPDAT is more likely to utilize phosphatidylcholine and phosphatidylethanolamine on the chloroplast endoplasmic reticulum membrane as the acyl donors. Especially, NoPDAT transferred the EPA acyl moiety from the sn-2 position of the two above-mentioned phospholipids to the sn-3 position of TAG, resulting in the increase of two major EPA-containing TAG molecules (16:1/16:0/20:5 and 16:1/16:1/20:5). Correspondingly, two major 16:0-containing TAG molecules (16,0/16:1/16:1 and 16:0/16:0/16:1) decreased in the transgenic strains. In conclusion, our attempt to express NoPDAT in P. tricornutum increases the EPA content in TAG by approximately one-fold, and demonstrates the versatility of diatom lipid metabolism and acyl editing.

EgbHLH63 negatively regulates palm fruit oil accumulation by repressing EgDGAT1 transcription

Diacylglycerol acyltransferase (DGAT) is a crucial enzyme involved in triacylglycerol (TAG) accumulation. To investigate the regulation of DGAT genes in the mesocarp of oil palm, a key transcription factor, EgbHLH63, was identified by a yeast one-hybrid assay. The interaction between EgbHLH63 and the EgDGAT1 promoter (proEgDGAT1) and its potential role in TAG synthesis were investigated. Binding of EgbHLH63 to proEgDGAT1 was confirmed by dual-luciferase reporter gene assays and EMSA in vitro. Overexpression of EgbHLH63 in oil palm protoplasts resulted in a significant reduction in EgDGAT1 expression. Silence of EgbHLH63 in transgenic embryoids restored high levels of EgDGAT1 expression and significantly increased TAG content. In addition, two other transcription factors, EgULT1 and EgZFP, were identified as interacting with EgbHLH63. They recognized B-box and AT-rich motifs in the EgDGAT1 promoter, respectively. These two transcription factors also negatively regulated EgDGAT1 expression, thereby affecting oil accumulation. Collectively, the results shed light on the lipid mechanism pathway involving EgDGAT1 in the mesocarp and offer promising research avenues for improving oil yield and quality in oil palm.

Chinese migrants exhibit impaired postprandial lipaemia compared to Caucasian counterparts following both high fat and high carbohydrate test meals.

People of Chinese ethnicity develop type 2 diabetes mellitus (T2DM) at a younger age and lower body mass index (BMI) than their Caucasian counterparts. Furthermore, Chinese migrants to Westernised countries have an increased risk of metabolic diseases compared to those in their country of origin(1,2). We propose that this increased risk is due to a greater manifestation of metabolic abnormalities in response to altered diet and lifestyle behaviours. Although fasting lipaemia and glycaemia are commonly used to predict risk of CVD and T2DM, assessment of impaired postprandial metabolism has been found to be a more sensitive indicator of risk(3). We hypothesised that Chinese migrants, at risk of T2DM, exhibit impaired postprandial lipid and lipoprotein metabolism compared to Australian-born Caucasian counterparts. Chinese and Caucasian adults at risk of T2DM were recruited to the study in which postprandial lipaemia and glycaemia were monitored following consumption of a high fat and high carbohydrate breakfast meal followed by a mixed, lunch meal. In a nonrandomised acute crossover trial, 15 adults (n = 8 Chinese and n = 7 Caucasian) aged ≥ 18 and ≤ 65 years at risk of T2DM (AUSDRISK score &gt; 12 (median = 14.0, IQR = 3.0)), attended two postprandial test days separated by ≥ 7-day washout period. Test breakfast meals were isocaloric (3.6 MJ), high fat (46% energy from fat, 46% energy from carbohydrates) or high carbohydrate (74% E carbohydrates, 17.5% E fat). Blood samples were collected at baseline (fasting), 180 min and 360 min after consumption of the breakfast meal. The lunch meal (3.7 MJ, 18% E fat, 76% E carbohydrates) was consumed 240 min after baseline. Samples were analysed for lipaemia and glycaemia. Additionally, chylomicron-rich, and VLDL-rich lipoprotein fractions were isolated by sequential ultracentrifugation and chylomicron particle number (apolipoprotein (apo) B48), triacylglycerol (TAG), and total cholesterol were assessed in these fractions. Data were analysed using a mixed between-within-subject analysis of variance. There were no differences in age, and baseline anthropometric measures between groups, apart from the Chinese group exhibiting significantly lower waist circumference and BMI compared to the Caucasian group. There were no differences between groups in blood measures, apart from a higher total- and LDL-cholesterol concentration in the Caucasian compared to the Chinese group (P&lt;0.05). Despite identical fasting TAG concentrations, the Chinese group, compared with the Caucasian group exhibited significantly elevated serum TAG and chylomicron-apo-B48 concentrations at 360 min following both test meals (P&lt;0.01). All other postprandial measures were not different between groups. These findings show that despite having identical or improved fasting glycaemia and lipid profile, the Chinese group exhibited impaired postprandial lipid metabolism which may contributes to their increased risk of metabolic diseases.

Rumen-Protected Choline Improves Metabolism and Lactation Performance in Dairy Cows.

Choline is required for the synthesis of phosphatidylcholine, an important constituent of lipoproteins. Early lactation cows presumably synthesize insufficient phosphatidylcholine, and choline supplementation in a rumen-protected form might benefit metabolism and lactation. The objectives of this study were to determine the effects of feeding rumen-protected choline (RPC) on lactation and metabolism in dairy cows. In experiment 1, 369 nulliparous and parous Holstein cows housed in four pens per treatment were fed 12.9 g/day of choline as RPC from 25 days prepartum until 80 days postpartum. In experiment 2, 578 nulliparous cows housed in five pens/treatment were fed 12.9 g/day of choline as RPC in the last 22 days of gestation only. In both experiments, blood was sampled and analyzed for concentrations of nonesterified fatty acids (NEFAs) and glucose at 1, 14, and 21 days postpartum and of choline at 1 and 14 days postpartum. Blood from all cows was sampled and analyzed for concentrations of β-OH butyrate (BHB) at 1 and 14 days postpartum. Cows with BHB > 1.2 mmol/L were classified as having hyperketonemia. Hepatic tissue was collected from 46 cows from the eight pens in experiment 1 at 9 days postpartum and analyzed for concentrations of glycogen and triacylglycerol. Milk yield and components were measured for 80 days postpartum in experiment 1, whereas only milk yield was measured in experiment 2. The pen was the experimental unit of analysis. Supplementing RPC tended to increase dry matter intake (DMI) prepartum in experiments 1 and 2 and postpartum in experiment 1. Feeding cows with RPC increased yields of 3.5% fat-corrected milk (42.8 vs. 44.8 kg/day), energy-corrected milk (38.5 vs. 40.3 kg/day), milk fat (1.52 vs. 1.61 kg/day), and true protein (1.16 vs. 1.21 kg/day) in experiment 1. Milk yield tended to be greater with RPC (26.4 vs. 27.4 kg/day) in experiment 2. Supplementing RPC increased plasma choline concentrations on day 14 postpartum in experiment 1 (3.32 ± 0.27 vs. 4.34 ± 0.28 µM) and on day 1 in experiment 2 (3.35 ± 0.16 and 13.73 ± 0.15 µM). Treatment did not affect the concentrations of glucose, NEFAs, or BHB in plasma, but the incidence of hyperketonemia was less in multiparous cows fed RPC than those fed the control in experiment 1. Feeding cows with RPC reduced hepatic triacylglycerol content and tended to reduce the ratio of triacylglycerol to glycogen and the risk of hepatic lipidosis in cows in experiment 1. The concentrations of hepatic triacylglycerol on day 9 postpartum were inversely related to those of choline in plasma on day 1 postpartum. Feeding cows with RPC improved lactation and metabolism, but more benefits were noted when it was fed before and after calving.

M1-derived extracellular vesicles polarize recipient macrophages into M2-like macrophages and alter skeletal muscle homeostasis in a hyper-glucose environment

BackgroundMacrophages release not only cytokines but also extracellular vesicles (EVs). which are small membrane-derived nanovesicles with virus-like properties transferring cellular material between cells. Until now, the consequences of macrophage plasticity on the release and the composition of EVs have been poorly explored. In this study, we determined the impact of high-glucose (HG) concentrations on macrophage metabolism, and characterized their derived-EV subpopulations. Finally, we determined whether HG-treated macrophage-derived EVs participate in immune responses and in metabolic alterations of skeletal muscle cells.MethodsTHP1-macrophages were treated with 15mM (MG15) or 30mM (MG30) glucose. Then, M1/M2 canonical markers, pro- and anti-inflammatory cytokines, activities of proteins involved in glycolysis or oxidative phosphorylation were evaluated. Macrophage-derived EVs were characterized by TEM, NTA, MRSP, and 1H-Nuclear magnetic resonance spectroscopy for lipid composition. Macrophages or C2C12 muscle cells were used as recipients of MG15 and MG30-derived EVs. The lipid profiles of recipient cells were determined, as well as proteins and mRNA levels of relevant genes for macrophage polarization or muscle metabolism.ResultsUntreated macrophages released small and large EVs (sEVs, lEVs) with different lipid distributions. Proportionally to the glucose concentration, glycolysis was induced in macrophages, associated to mitochondrial dysfunction, triacylglycerol and cholesterol accumulation. In addition, MG15 and MG30 macrophages had increased level of CD86 and increase release of pro-inflammatory cytokines. HG also affected macrophage sphingolipid and phospholipid compositions. The differences in the lipid profiles between sEVs and lEVs were abolished and reflected the lipid alterations in MG15 and MG30 macrophages. Interestingly, MG15 and MG30 macrophages EVs induced the expression of CD163, Il-10 and increased the contents of triacylglycerol and cholesterol in recipient macrophages. MG15 lEVs and sEVs induced insulin-induced AKT hyper-phosphorylation and accumulation of triacylglycerol in myotubes, a state observed in pre-diabetes. Conversely, MG30 lEVs and sEVs induced insulin-resistance in myotubes.ConclusionsAs inflammation involves first M1 macrophages, then the activation of M2 macrophages to resolve inflammation, this study demonstrates that the dialog between macrophages through the EV route is an intrinsic part of the inflammatory response. In a hyperglycemic context, EV macrophages could participate in the development of muscle insulin-resistance and chronic inflammation.

Vine tea total flavonoids activate the AMPK/mTOR pathway to amelioration hepatic steatosis in mice fed a high-fat diet.

Vine tea (Ampelopsis grossedentata), a traditional Chinese tea, is rich in flavonoids with various biological activities. Our study found that Vine tea total flavonoids (TFs) treatment reduced the body mass and blood lipid levels and improved the hepatic tissue morphology in mice fed the high-fat diet (HFD). In vivo, TF treatment activated the hepatic adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, initiated autophagy, and regulated the expression levels of proteins for lipid metabolism in those HFD-fed mice. In vitro, TF treatment dramatically reduced the lipid droplets and triacylglycerol content in HepG2 and L02 cells treated with oleic acid (OA). These were associated with the activation of the AMPK/mTOR pathway and autophagy initiation in OA-treated hepatocytes. This phenotype was abolished in the presence of 3-methyladenine, an autophagy inhibitor. Our results indicated that the TF activation of AMPK/mTOR leads to the stimulation of autophagy and a decrease in the buildup of intracellular lipids in hepatocytes, showing the potential of TF as a therapeutic agent for nonalcoholic fatty liver disease. PRACTICAL APPLICATION: Vine tea, a tea drink, has been consumed by Chinese folk for over a thousand years. The result of this study will provide evidence that vine tea total flavonoids have potential use as a functional material for the prevention and amelioration of nonalcoholic fatty liver disease.

Exploring the Relationship Among Lipid Profile Changes, Growth, and Reproduction in Folsomia candida Exposed to Teflubenzuron Over Time.

The integration of untargeted lipidomics approaches in ecotoxicology has emerged as a strategy to enhance the comprehensiveness of environmental risk assessment. Although current toxicity tests with soil microarthropods focus on species performance, that is, growth, reproduction, and survival, understanding the mechanisms of toxicity across all levels of biological organization, from molecule to community is essential for informed decision-making. Our study focused on the impacts of sublethal concentrations of the insecticide teflubenzuron on the springtail Folsomia candida. Untargeted lipidomics was applied to link changes in growth, reproduction, and the overall stress response with lipid profile changes over various exposure durations. The accumulation of teflubenzuron in organisms exposed to the highest test concentration (0.035 mg a.s. kg-1 soil dry wt) significantly impacted reproductive output without compromising growth. The results suggested a resource allocation shift from reproduction to size maintenance. This hypothesis was supported by lipid shifts on day 7, at which point reductions in triacylglycerol and diacylglycerol content corresponded with decreased offspring production on day 21. The hypermetabolism of fatty acids and N-acylethanolamines on days 2 and 7 of exposure indicated oxidative stress and inflammation in the animals in response to teflubenzuron bioaccumulation, as measured using high-performance liquid chromatography-tandem mass spectrometry. Overall, the changes in lipid profiles in comparison with phenotypic adverse outcomes highlight the potential of lipid analysis as an early-warning tool for reproductive disturbances caused by pesticides in F. candida. Environ Toxicol Chem 2024;00:1-12. © 2024The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Knockdown of PROX1 promotes milk fatty acid synthesis by targeting PPARGC1A in dairy goat mammary gland

Goat milk is rich in various fatty acids that are beneficial to human health. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and RNA-seq analyses of goat mammary glands at different lactation stages revealed a novel lactation regulatory factor, Prospero homeobox 1 (PROX1). However, the mechanism whereby PROX1 regulates lipid metabolism in dairy goats remains unclear. We found that PROX1 exhibits the highest expression level during peak lactation period. PROX1 knockdown enhanced the expression of genes related to de novo fatty acid synthesis (e.g., SREBP1 and FASN) and triacylglycerol (TAG) synthesis (e.g., DGAT1 and GPAM) in goat mammary epithelial cells (GMECs). Consistently, intracellular TAG and lipid droplet contents were significantly increased in PROX1 knockdown cells and reduced in PROX1 overexpression cells, and we observed similar results in PROX1 knockout mice. Following PROX1 overexpression, RNA-seq showed a significant upregulation of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A) expression. Further, PPARGC1A knockdown attenuated the inhibitory effects of PROX1 on TAG contents and lipid-droplet formation in GMECs. Moreover, we found that PROX1 promoted PPARGC1A transcription via the PROX1 binding sites (PBSs) located in the PPARGC1A promoter. These results suggest a novel target for manipulating the goat milk-fat composition and improving the quality of goat milk.

The transcription factor MYB1 activates DGAT2 transcription to promote triacylglycerol accumulation in sacha inchi (Plukenetia volubilis L.) leaves under heat stress

Triacylglycerol (TAG) accumulation is frequently triggered in vegetative tissues experiencing heat stress, which may increases plant basal plant thermo-tolerance by sequestering the toxic lipid intermediates that contribute to membrane damage or cell death under stress conditions. However, stress-responsive TAG biosynthesis and the underlying regulatory mechanisms are not fully understood. Here, we investigated the lipidomic and transcriptomic landscape under heat stress in the leaves of sacha inchi (Plukenetia volubilis L.), an important oilseed crop in tropical regions. Under heat stress (45 °C), the content of polyunsaturated TAGs (e.g., TAG18:2 and TAG18:3) and total TAGs were significantly higher, while those of unsaturated sterol esters, including ZyE 28:4, SiE 18:2 and SiE 18:3, were dramatically lower. Transcriptome analysis showed that the expression of PvDGAT2-2, encoding a type II diacylglycerol acyltransferase (DGAT) that is critical for TAG biosynthesis, was substantially induced under heat stress. We confirmed the function of PvDGAT2-2 in TAG production by complementing a yeast mutant defective in TAG biosynthesis. Importantly, we also identified the heat-induced transcription factor PvMYB1 as an upstream activator of PvDGAT2-2 transcription. Our findings on the molecular mechanism leading to TAG biosynthesis in leaves exposed to heat stress have implications for improving the biotechnological production of TAGs in vegetative tissues, offering an alternative to seeds.

Quantum dot-based light conversion strategy for customized cultivation of microalgae

Microalgae are photosynthetic microorganisms with the potential to mitigate the atmospheric greenhouse effect by carbon fixation. However, their growth is typically limited by light availability. A wavelength converter utilizing red, blue, and green quantum dots (QDs) was developed to optimize light quality for enhancing microalgal production. The growth, lipid content, and eicosapentaenoic acid titer of Nannochloropsis increased by 11.2%, 9.5%, and 15.5% with red QDs, respectively. The biomass and triacylglycerol content of Phaeodactylum tricornutum increased by 8.6% and 35.0%, respectively. Simultaneously, biodiesel production was accelerated in Nannochloropsis (20.2%) and P. tricornutum (11.6%), and improved with increased cetane number and reduced iodine value. Furthermore, red QDs increased the growth and biomass accumulation of Nannochloropsis under low light, while green QDs shielded Nannochloropsis from photoinhibition under high light. This customizable QD-based methodology overcomes microalgal light limitations, demonstrating a universally applicable approach to improve microalgal cultivation and biochemical component production.

Effect of rumen-protected choline on fat digestibility and lymph metabolome in dairy cows.

Objectives were to determine the effects of supplementing rumen-protected choline (RPC) from an established source with low (L, 28.8%) or a prototype with less lipid coating protection and high (H, 60.0%) concentrations of choline chloride on digestibility of fat and supra-mammary lymph metabolome in feed-restricted cows. Pregnant, nonlactating Holstein cows (n = 33; 11/treatment) at mean (±standard deviation) 231 ± 4.7 days of gestation were blocked by body condition (4.23 ± 0.47) and assigned to receive 0 (CON) or 25.8 g/d of choline ion from L (L25.8) or H (H25.8). Cows were adapted to the diet and then fed-restricted to 42% of the net energy of lactation required for maintenance and pregnancy for 9 days. Intake of metabolizable methionine was maintained at 19 g/d. On Day 9, cows were fed 450 g of saturated fatty acids (SFA), and feces and blood were sampled continuously for 24 h. Supra-mammary lymph was sampled 6 h after feeding SFA and metabolome was characterized. Feeding RPC increased digestibility of fat (CON = 80.4 vs. RPC = 86.0 ± 1.9%) and reduced the concentration of haptoglobin in serum (CON = 174 vs. RPC = 77 ± 14 µg/ml) independent of source of RPC fed. Feeding RPC increased the concentrations of triacylglycerol in serum (CON = 15.1 vs. RPC = 17.8 ± 1.9 mg/dl) in feed-restricted cows after feeding SFA, and the increment tended to be greater for cows fed H25.8 than L25.8. Supplementing RPC tended to increase the concentrations of triacylglycerol (CON = 11.4 vs. RPC = 15.8 ± 3.4 mg/dl) in supra-mammary lymph. Feeding RPC increased the concentration of choline and affected the concentrations of analytes involved in metabolic pathways associated with amino acid metabolism and biosynthesis of phospholipids in lymph compared with CON. Feeding RPC, independent of source used, increased fat digestibility with some changes in lymph metabolome in cows under negative nutrient balance.

Study of Correlation of Serum Adiponectin Concentration with Different Lipid Profile Components

Adiponectin is a hormone, secreted from adipose tissue. It is inversely correlated with body fat mass. This hormone has also anti-inflammatory and ant-iatherogenic properties. This study was purposed to explore the relationship between serum adiponectin concentration and lipid profile. This cross-sectional analytical study was carried out in the Department of Biochemistry, Bangabandhu Sheikh Mujib Medical University (BSMMU) from March 2016 to February 2017. By non-probability sampling, a total of 156 study subjects were selected from apparently healthy adult individuals attending outpatient department of BSMMU. Serum adiponectin level positively correlated with serum HDL cholesterol (r=0.246, p value 0.002) concentrations and negatively correlated with serum total cholesterol (r=-0.171, p value 0.033) and serum triacylglycerol level (r=-0.3, p value 0.00). So, from this study it can be concluded that adiponectin has an important role in the metabolism of lipid profile components and responsible for controlling the concentration of serum lipid profile components. When adiponectin concentration of blood increases it is responsible for raised serum HDL-C concentration and decreased total cholesterol and triacylglycerol concentration.&#x0D; Bangladesh J Med Biochem 2019; 12(1): 6-10

Fatty Acid Elongase Gene PcELO7 is Essential for Lipid Accumulation and Fecundity of Panonychus citri (Acari: Tetranychidae).

RNA interference (RNAi) has been proposed as a promising strategy for sustainable and ecofriendly pest control. The insect cuticle lipids were deposited on the body surface and functioned as a defense against chemical xenobiotics. They consisted of aliphatic compounds, including free fatty acids (FFAs). However, elongase of very long chain fatty acids (ELOs) is essential for FFA biosynthesis; the function of ELO is still unknown in many arthropods, including Panonychus citri (P. citri). In this study, three ELOs were cloned. Developmental-specific mRNA expression results revealed that three PcELOs were highly expressed in egg and adult females. Whereas PcELO7 was dominantly expressed in adult females. Under spirobudiclofen stress, ELOs mRNA expression had different changes, and PcELO7 was down-regulated. The silencing of PcELO7 resulted in a dramatic reduction of oviposition and hatchability. Significant reduction of FFA contents was also examined within PcELO7-repressed P. citri. In addition, we found that PcELO7 mRNA levels were related to fecundity and could affect triacylglycerol (TG) contents. The findings demonstrated that the introduction of dsPcELO7 via oral feeding induced the RNA interference-mediated silencing of a special target gene and could result in mortality and reproduction. In conclusion, PcELO7 is a special RNAi target for P. citri control, and its lethal mechanism might be disturbing lipids biosynthesis.