Expression Of Fatty Acid Desaturase Research Articles

Improved chilling tolerance in glasshouse-grown potted sweet basil by end-of-production, short-duration supplementary far red light.

Sweet basil is a popular culinary herb used in many cuisines around the world and is widely grown commercially for retail as a live potted plant. However, basil is easily damaged by temperatures below 12 °C meaning plants must be transported from the grower to the retailer in a warm transport chain, adding considerable commercial cost in temperate countries. Improvement of chilling tolerance has been demonstrated in post-harvest crops such as tomato fruits and, indeed, fresh cut basil, by manipulation of the red:far red ratio of light provided to plants throughout the photoperiod and for a significant duration of the growing process in controlled environment chambers. We tested the effectiveness of periodic short-duration end-of-production supplementary far red light treatments designed for use with basil plants grown in a large scale commercial glasshouse for the live potted basil market. Four days of periodic, midday supplementary far red light given at end of production induced robust tolerance to 24 h of 4 °C cold treatment, resulting in greatly reduced visual damage, and reduced physiological markers of chilling injury including electrolyte leakage and reactive oxygen species accumulation. Antioxidant levels were also maintained at higher levels in live potted basil following this cold treatment. RNAseq-based analysis of gene expression changes associated with this response pointed to increased conversion of starch to soluble raffinose family oligosaccharide sugars; increased biosynthesis of anthocyanins and selected amino acids; inactivation of gibberellin signaling; and reduced expression of fatty acid desaturases, all previously associated with increased chilling tolerance in plants. Our findings offer an efficient, non-invasive approach to induce chilling tolerance in potted basil which is suitable for application in a large-scale commercial glasshouse.

A unique inflammation-related mechanism by which high-fat diets induce depression-like behaviors in mice

BackgroundHigh-fat diet (HFD) consumption is an important reason for promoting depression, but the mechanism is unclear. The present study aims to explore the relationship between metabolic disturbance and HFD-induced depression-like behaviors. MethodsDepression models were established by HFD consumption and chronic unpredictable mild stress (CUMS) in mice. Enzyme-linked immunosorbent assay, western blotting, real-time polymerase chain reaction, gas chromatography and metabolomic analysis were undertaken to investigate the 5-hydroxytryptamine (5-HT) system, neuroinflammation and to identify altered lipid metabolic pathways. ResultsDepression-like behaviors, impaired 5-HT neurotransmission and disordered lipid metabolism were observed upon HFD consumption. Despite a similar reduction of high-density lipoprotein cholesterol in CUMS and HFD group, high levels of body low-density lipoprotein cholesterol in the HFD group could help distinguish HFD from CUMS. Levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α and inflammation-related metabolites were increased in HFD mice, so a link between depression and inflammation was postulated. Different metabolites were enriched in the two groups. The linoleic acid (LA) metabolic pathway and expression of fatty acid desaturase (FADS)1 and FADS2 (key enzymes in LA metabolic pathway) were enhanced significantly in HFD mice compared with the control group. LimitationsCausality analyses for HFD and inflammation-related features were not undertaken. ConclusionsHFD-induced depression-like behaviors was characterized by more severely disordered metabolism of lipids (especially in the LA metabolic pathway) and increased levels of inflammatory mediators, which might be the reasons for the disturbance of serotonergic system in hippocampus.

Dietary omega-3 fatty acid deficiency from pre-pregnancy to lactation affects expression of genes involved in hippocampal neurogenesis of the offspring

Maternal n-3 PUFA (omega-3) deficiency can affect brain development in utero and postnatally. Despite the evidence, the impacts of n-3 PUFA deficiency on the expression of neurogenesis genes in the postnatal hippocampus remained elusive. Since postnatal brain development requires PUFAs via breast milk, we examined the fatty acid composition of breast milk and hippocampal expression of neurogenesis genes in n-3 PUFA deficient 21d mice. In addition, the expression of fatty acid desaturases, elongases, free fatty acids signaling receptors, insulin and leptin, and glucose transporters were measured. Among the genes involved in neurogenesis, the expression of brain-specific tenascin-R (TNR) was downregulated to a greater extent (∼31 fold), followed by adenosine A2A receptor (A2AAR), dopamine receptor D2 (DRD2), glial cell line-derived neurotrophic factor (GDNF) expression in the n-3 PUFA deficient hippocampus. Increasing dietary LA to ALA (50:1) elevated the ARA to DHA ratio by ∼8 fold in the n-3 PUFA deficient breast milk, with an overall increase of total n-6/n-3 PUFAs by ∼15:1 (p<0.05) compared to n-3 PUFA sufficient (LA to ALA: 2:1) diet. The n-3 PUFA deficient mice exhibited upregulation of FADS1, FADS2, ELOVL2, ELOVL5, ELOVL6, GPR40, GPR120, LEPR, IGF1 and downregulation of GLUT1, GLUT3, and GLUT4 mRNA expression in hippocampus (p<0.05). Maternal n-3 PUFA deficiency affects the hippocampal expression of key neurogenesis genes in the offspring with concomitant expression of desaturase and elongase genes, suggesting the importance of dietary n-3 PUFA for neurodevelopment.

Placental expression of Fatty Acid Desaturases 1, 2 and 3 in selected pregnancy pathologies.

Intrauterine development is a key period in human life. The foetal progress largely depends on the function of the placenta, whose responsibility is transportation and biosynthesis of fatty acids. Desaturation enzymes play a key role in placental fatty acid metabolism. Expression of genes coding for desaturases may be associated with pregnancy abnormalities. The objective of this study was to determine the transcriptional activity of the placental genes Fatty Acid Desaturases 1, 2 and 3 (FADS 1, 2 and 3) in women who gave birth to the infants appropriate for gestational age, large for gestational age, small for gestational age, with intrauterine growth restriction and born preterm. 34 pregnant women aged 21-37 years old participated in the study. The placental samples were taken from a site located 2-3 cm away from the umbilical cord attachment. The collected tissue sections were stored in RNAlater according to the manufacturer's protocol, until required for molecular analysis. The expression profiles of FADS1, FADS2 and FADS3 were determined with RT-qPCR. There was no difference in FADS1 and FADS2 expression between the groups. However, the differences in the expression of the FADS3 were found. Analysis of the FADS1, FADS2 and FADS3 transcription showed significant differences between most of the examined groups. Our findings suggest that the transcriptional activity of FADS genes changes with the severity of intrauterine disorders and is associated with foetal lipid disorders linked to a greater accumulation of fat in the foetal tissues.

Identification and characterization of fatty acid desaturases in Schizochytrium sp. HX-308

As a promising species of the thraustochytrids , Schizochytrium sp. has attracted extensive attention due to its ability to produce high levels of polyunsaturated fatty acids . In Schizochytrium sp. HX-308, there was a complete anaerobic polyketide synthase (PKS) pathway and an incomplete aerobic desaturase/elongase pathway. However, it is still quite unclear which fatty acid desaturases are involved in fatty acid desaturation in Schizochytrium sp. and how they act in concert. In this work, we firstly identified five putative desaturases in Schizochytrium sp. HX-308, including Δ12, two Δ8, Δ6, and Δ5 fatty acid desaturase genes. They were heterologously expressed in Yarrowia lipolytica and the first four fatty acid desaturases were verified as functional. Δ12 desaturase contributes to a significant increase in the content of C18:2Δ 9, 12 fatty acids, from 17.26 % to 28.46 %. The expression of two Δ8 desaturases resulted in an increase in C20:3Δ 8, 11, 14 content, from 3.84 % to 7.29 % and 6.82 %, respectively. Δ6 desaturase enables the PO1F strain to produce a new fatty acid C18:3Δ 6, 9, 12 , reaching 9.73 % of the total fatty acids. Although the expression of Δ5 desaturase didn't produce C20:4 Δ 5, 8, 11, 14 fatty acids, it significantly decreased the content of C18:1Δ 9 and C18:2Δ 9, 12 fatty acids and largely significantly increased C18:3Δ 6, 9, 12 and C20:2Δ 11, 14 fatty acid content. This work will provide valuable insights into the optimization of the polyunsaturated fatty acid composition of Schizochytrium sp. through genetic engineering in the future. • Identification and characterization of five fatty acid desaturases in Schizochytrium sp. HX-308. • Heterologous expression of fatty acid desaturases changed the fatty acid profile of Y. lipolytica . • Heterologous expression of fatty acid desaturases enhances the production of PUFAs in Y. lipolytica .

Yiqi-Bushen-Tiaozhi Recipe Attenuated High-Fat and High-Fructose Diet Induced Nonalcoholic Steatohepatitis in Mice via Gut Microbiota

AimTo investigate the treating effect of Yiqi-Bushen-Tiaozhi (YBT) recipe on nonalcoholic steatohepatitis (NASH) mice, determine whether the outcome was associated with gut microbiota, and clarify the regulating mechanism.MethodsNASH mice were induced by high-fat and high-fructose diets (HFFD). In the fifth week, mice in the YBT group were orally administrated YBT (22.12g·kg-1·d-1) daily for 12 weeks. Fresh stool of mice was collected at the 16th week for fecal 16S rDNA analysis. Hepatic pathology and biochemical indicators were used to reflect the improvement of YBT on hepatic inflammation and lipid metabolism in NASH mice. Quantitative real-time PCR (qRT-PCR) was used to verify the results of PICRUSt analysis.ResultsResults of the pathological and biochemical index showed that YBT could improve NASH mice. Compared with improving inflammation and hepatocyte damage, YBT may be more focused on enhancing metabolic disorders in mice, such as increasing HDL-c level. The diversity and richness of the gut microbiota of NASH mice induced by HFFD are significantly different from the normal control (NC) group. After YBT treatment, the diversity and richness of the mice microbiota will be increased to similar NC mice. Intestinimonas, Acetatifactor, Alistipes, Intestinimonas, Acetatifactor, and Alistipes have the most significant changes in the class level. PICRUSt analysis was performed to predict genomic functions based on the 16S rDNA results and reference sequencing. The efficacy of YBT in the treatment of NASH can be achieved by regulating the diversity and richness of gut microbiota. PICRUSt analysis results showed that the most relevant function of the microbiota construction variations is α- Linolenic acid (ALA) metabolism. Results of qRT-PCR showed significant differences between groups in the expression of Fatty acid desaturase 1 (FADS1), Fatty acid desaturase 2 (FADS2), Acyl-CoA Oxidase 1 (ACOX1), and Acyl-CoA Oxidase 2 (ACOX2) related to ALA metabolism. The expression of the above genes will be inhibited in the liver and small intestine of the HFFD group mice, and the expression can be restored after YBT treatment.ConclusionYBT could treat NASH mice by improving the diversity and richness of gut microbiota and further the improvement of ALA metabolism.

Abstract WP229: Eicosapentaenoic Acid (EPA) Modulates Expression Of Thrombotic And Metabolic Proteins In Brain Endothelium Following Cytokine Challenge

Background: During inflammation, vascular endothelial cells (ECs) release vasoconstrictive and thrombotic factors that promote abnormal blood flow and atherothrombosis. The omega-3 fatty acid (n3FA) eicosapentaenoic acid (EPA) reduced first and total ischemic strokes each by 36% in patients with elevated cardiovascular risk (REDUCE-IT) when administered as icosapent ethyl. We measured the effects of EPA on expression of proteins involved in cytoprotection, thrombosis, and fatty acid metabolism in human brain ECs subjected to inflammation. Methods: Human brain microvascular ECs (HBECs) were first challenged with IL-6 at 12 ng/ml for 2 hr and then treated with EPA (40 μM) for 24 hr. Global proteomic analysis was performed using LC/MS to measure relative expression levels of &gt;1,000 proteins simultaneously. Only significant (p&lt;0.05) changes in expression between treatment groups &gt;1-fold were analyzed. Results: EPA treatment significantly modulated the expression of 504 proteins (212 increased expression, 292 decreased expression) in HBECs compared with IL-6 alone. EPA treatment increased expression of the cytoprotective enzyme heme oxygenase-1 by 1.5-fold (p = 4.7 х 10 -16 ) relative to IL-6 alone. Additionally, IL-6 increased expression of prothrombin (clotting factor II) 1.3-fold relative to control (p = 1.41 х 10 -20 ), and EPA decreased expression of prothrombin by 1.3-fold relative to IL-6 (p = 2.10 х 10 -24 ). EPA also reduced expression of fatty acid desaturase 1 &amp; 2 by 1.4-fold and 2.6-fold, respectively, which may lead to changes in intracellular fatty acid levels. Conclusions: EPA significantly modulated expression of cytoprotective, thrombotic, and metabolic proteins in brain ECs under conditions of inflammation with IL-6. These effects of EPA on inflammation have implications for ischemic disease, including stoke, as demonstrated in large outcome trials.

To Explore Ideas From the Altered Metabolites: The Metabolomics of Pathological Scar.

Pathological scars are dermal fibroproliferative disorders due to rapid inflammatory response after dermal injury. The altered metabolites could reflect pathophysiological changes directly. However, it has not cleared how the metabolites change scars. To explore new ideas of pathological scars from the altered metabolites by using ultra-performance liquid chromatography coupled to tandem mass spectrometry and identifying the key genes. Keloid (KS, n = 10), hypertrophic scar (HS, n = 10), and normal skin (NS, n = 10) were collected. Ultra-performance liquid chromatography coupled to tandem mass spectrometry was used to identify and characterize metabolites. Differential metabolites were analyzed by orthogonal partial least square discriminant analysis and Student t test. The key pathways were analyzed via Kyoto Encyclopedia of Genes and Genomes, and the related enzymes were verified by real-time Polymerase Chain Reaction, both in tissues and their dermal fibroblasts. Two hundred fourteen metabolites were detected in total, mostly were fatty acids and amino acids. In the KS and NS groups, 65 different metabolites were screened ( P < 0.05), and the polyunsaturated fatty acids (PUFAs) metabolism and butyric acid in keloid should be concerned. The messenger Ribonucleic Acid expression of fatty acid desaturase 1 and fatty acid desaturase 2, which are the key enzyme of PUFA metabolism, were lower in KS and keloid-derived fibroblasts, P < 0.05. In HS group, 17 metabolites were significantly different and branched chain amino acids degradation was the key pathway. Moreover, branched chain keto acid dehydrogenase E1 subunit alpha was lower expressed in HS and their fibroblasts compared with NS, P < 0.05. Polyunsaturated fatty acids and butyric acid may be associated with the generation of keloids. The pathogenesis of hypertrophic scars may be involved in branched chain amino acids degradation, which is worth paying attention to.

Gibberellic acid-induced fatty acid metabolism and ABC transporters promote astaxanthin production in Phaffia rhodozyma.

Astaxanthin is an important natural antioxidant with various biological functions; however, the production of astaxanthin does not meet the requirements for industrialization. The aim of the present study was to identify an inducer that increases astaxanthin yield and to evaluate the regulatory mechanism of the induction of astaxanthin synthesis in Phaffia rhodozyma. The effects of indole-3-acetic acid (IAA), jasmonic acid (JA) and gibberellic acid (GA) on astaxanthin synthesis were studied by fermentation kinetics analysis. Then, combined transcriptomics and metabolomics approaches were used to analyse differential metabolites and expressed genes involved in astaxanthin synthesis induced by GA. The results indicated that GA significantly increased astaxanthin production; however, IAA and JA had no significant effect on astaxanthin synthesis. The induction by GA significantly enhanced fatty acid metabolism and ABC transporters, increased the expression of fatty acid desaturase and ABC transporter genes, and elevated the contents of unsaturated fatty acids. These results suggested that fatty acid saturation plays an important role in astaxanthin accumulation and that ABC transporters may be the efflux pumps for astaxanthin. The present study reveals metabolic mechanism of GA-induced astaxanthin synthesis and proposes a new strategy of transporter engineering to improve astaxanthin production.

MicroRNA-193a-5p Regulates the Synthesis of Polyunsaturated Fatty Acids by Targeting Fatty Acid Desaturase 1 (FADS1) in Bovine Mammary Epithelial Cells.

Cardiovascular diseases (CVDs) are seriously threatening to human life and health. Polyunsaturated fatty acids (PUFAs) are known for their role in preventing CVDs. It is beneficial to population health to promote the content of PUFAs in bovine milk. In recent years, limited research based on molecular mechanisms has focused on this field. The biological roles of numerous microRNAs (miRNAs) remain unknown. In this study, a promising and negatively correlated pair of the miRNA (miRNA-193a-5p) and a fatty acid desaturase 1 (FADS1) gene are identified and screened to explore whether they are potential factors of PUFAs’ synthesis in bovine milk. The targeted relationship between miRNA-193a-5p and FADS1 in bovine mammary epithelial cells (BMECs) is demonstrated by dual luciferase reporter assays. qRT-PCR and western blot assays indicate that both the expression of mRNA and the protein FADS1 show a negative correlation with miRNA-193a-5p expression in BMECs. Also, miR-193a-5p expression is positively correlated with the expression of genes associated with milk fatty acid metabolism, including ELOVL fatty acid elongase 6 (ELOVL6) and diacylglycerol O-acyltransferase 2 (DGAT2). The expression of fatty acid desaturase 2 (FADS2) is negatively correlated with miR-193a-5p expression in BMECs. The contents of triglycerides (TAG), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) have a significant positive correlation with the expression of FADS1 and a significant negative correlation with the expression of miR-193a-5p in BMECs. For the first time, this study confirms that miRNA-193a-5p regulates PUFAs metabolism in BMECs by targeting FADS1, indicating that miRNA-193a-5p and FADS1 are underlying factors that improve PUFAs content in bovine milk.

Heat stress elicits remodeling in the anther lipidome of peanut

Understanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.

EGCG regulates fatty acid metabolism of high-fat diet-fed mice in association with enrichment of gut Akkermansia muciniphila

• EGCG regulated the profile of circulating fatty acids in serum. • EGCG decreased the expression of fatty acid desaturase in liver (SCD1 and FADS2). • EGCG shifted structure of gut microbiota and enriched Akkermansia muciniphilain . • Akkermansia muciniphila might take part in the regulation of fatty acid metabolism. This study is to examine the effects of EGCG on fatty acid metabolism and their possible relationship with gut microbiota. C57BL/6J mice fed with HFD were administrated with 210 mg/kg EGCG for 12 weeks. EGCG significantly decreased saturated fatty acids (C17:0 and C22:0), increased the unsaturated fatty acids (C18:1 and C18:2) ( p < 0.05) in the serum, and decreased the liver protein expression of SCD1 and FADS2. EGCG administration significantly enriched the Verrucomicrobia and decreased the Firmicutes and Saccharibacteria ( p < 0.05). Bacteroides, Candidatus_Saccharimonas and Akkermansia showed strong correlation with serum fatty acids profile ( p < 0.05, r > 0.45 or r < -0.45). Interestingly, Akkermansia muciniphila was positively correlated with C18:2 ( p < 0.05, r = 0.51) and negatively correlated with C22:0 ( p < 0.05, r = -0.48). These findings demonstrate that alteration of the circulating long chain fatty acids profile is involved in EGCG-mediated lipid metabolism of HFD-fed mice, and the intestinal Akkermansia muciniphila bacteria might play an important role in this process.

Reproductive performance of gilthead seabream (Sparus aurata) broodstock showing different expression of fatty acyl desaturase 2 and fed two dietary fatty acid profiles

Previous studies have shown that it is possible to nutritionally program gilthead seabream offspring through fish oil (FO) replacement by vegetable oils (VO) in the broodstock diet, to improve their ability to grow fast when fed low fish meal (FM) and FO diets during grow-out phase. However, in those studies broodstock performance was reduced by the VO contained diet. Therefore, the present study aimed to determine if it is possible to replace FO by a mixture of FO and rapeseed oil (RO) with a specific fatty acid profile in broodstock diets, without altering gilthead seabream broodstock reproductive performance. Besides, the study also aimed to evaluate the reproductive performance of broodstock with different expression of fatty acid desaturase 2 gene (fads2) a key enzyme in synthesis of long chain polyunsaturated fatty acids. For that purpose, broodfish having either a high (HD) or low (LD) expression of fads2 were fed for three months during the spawning season with two diets containing different fatty acid profiles and their effects on reproductive hormones, fecundity, sperm and egg quality, egg biochemical composition and fads2 expression were studied. The results showed that blood fads2 expression in females, which tended to be higher than in males, was positively related to plasma 17β-estradiol levels. Moreover, broodstock with high blood fads2 expression showed a better reproductive performance, in terms of fecundity and sperm and egg quality, which was correlated with female fads2 expression. Our data also showed that it is feasible to reduce ARA, EPA and DHA down to 0.43, 6.6 and 8.4% total fatty acids, respectively, in broodstock diets designed to induce nutritional programming effects in the offspring without adverse effects on spawning quality. Further studies are being conducted to test the offspring with low FM and FO diets along life span.

Leveraging a gain-of-function allele of Caenorhabditis elegans paqr-1 to elucidate membrane homeostasis by PAQR proteins.

The C. elegans proteins PAQR-2 (a homolog of the human seven-transmembrane domain AdipoR1 and AdipoR2 proteins) and IGLR-2 (a homolog of the mammalian LRIG proteins characterized by a single transmembrane domain and the presence of immunoglobulin domains and leucine-rich repeats in their extracellular portion) form a complex that protects against plasma membrane rigidification by promoting the expression of fatty acid desaturases and the incorporation of polyunsaturated fatty acids into phospholipids, hence increasing membrane fluidity. In the present study, we leveraged a novel gain-of-function allele of PAQR-1, a PAQR-2 paralog, to carry out structure-function studies. We found that the transmembrane domains of PAQR-2 are responsible for its functional requirement for IGLR-2, that PAQR-1 does not require IGLR-2 but acts via the same pathway as PAQR-2, and that the divergent N-terminal cytoplasmic domains of the PAQR-1 and PAQR-2 proteins serve a regulatory function and may regulate access to the catalytic site of these proteins. We also show that overexpression of human AdipoR1 or AdipoR2 alone is sufficient to confer increased palmitic acid resistance in HEK293 cells, and thus act in a manner analogous to the PAQR-1 gain-of-function allele.

Linseed oil supplementation affects fatty acid desaturase 2, peroxisome proliferator activated receptor gamma, and insulin-like growth factor 1 gene expression in turkeys (Meleagris gallopavo).

ObjectiveEffects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated.MethodsThe animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction.ResultsThe LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control.ConclusionFatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

Aging exacerbates high-fat diet-induced steatohepatitis through alteration in hepatic lipid metabolism in mice.

Aging is an independent risk factor for the progression of non-alcoholic steatohepatitis. Here, we investigated the role of age-related alterations in fatty acid metabolism in dietary steatohepatitis using lipidomics analysis. Male 8-week and 55-week-old C57BL/6J mice were fed a high-fat diet (HFD) for 8weeks. The quality and quantity of lipid molecular species in the liver were evaluated using the lipidomics approach. Elder mice fed an HFD developed more severe steatohepatitis than young mice. Oxidative stress and inflammatory cytokines in the liver were exacerbated following HFD feeding in elder mice compared with young mice. In elder mice, de novo fatty acid synthesis was promoted, whereas β oxidation was blunted following HFD feeding, and lipid secretion from the liver was reduced. The expression of sirtuin 1 was not only reduced with age as expected but also significantly decreased due to intake of HFD. In the lipidomics analysis, the concentrations of diacylglycerol and TAG molecular species containing monounsaturated fatty acids were markedly increased following HFD feeding in elder mice compared with young mice. In contrast, the concentration of phosphatidylethanolamine and phosphatidylcholine molecular species containing polyunsaturated fatty acids were remarkably decreased following HFD feeding in elder mice compared with young mice, and the expression of fatty acid desaturase was blunted. Aging-dependent alterations in lipid metabolism under excessive lipid supply most likely enhance hepatic lipotoxicity, thereby exacerbating metabolic steatohepatitis in elderly.

The expression of several pepper fatty acid desaturase genes is robustly activated in an incompatible pepper-tobamovirus interaction, but only weakly in a compatible interaction

The replication of positive strand RNA viruses in plant cells is markedly influenced by the desaturation status of fatty acid chains in lipids of intracellular plant membranes. At present, little is known about the role of lipid desaturation in the replication of tobamoviruses. Therefore, we investigated the expression of fatty acid desaturase (FAD) genes and the fatty acid composition of pepper leaves inoculated with two different tobamoviruses. Obuda pepper virus (ObPV) inoculation induced a hypersensitive reaction (incompatible interaction) while Pepper mild mottle virus (PMMoV) inoculation caused a systemic infection (compatible interaction). Changes in the expression of 16 FADs were monitored in pepper leaves following ObPV and PMMoV inoculations. ObPV inoculation rapidly and markedly upregulated seven Δ12-FADs that encode enzymes putatively located in the endoplasmic reticulum membrane. In contrast, PMMoV inoculation resulted in a weaker but rapid upregulation of two Δ12-FADs and a Δ15-FAD. The expression of genes encoding plastidial FADs was not influenced neither by ObPV nor by PMMoV. In accordance with gene expression results, a significant accumulation of linoleic acid was observed by gas chromatography-mass spectrometry in ObPV-, but not in PMMoV-inoculated leaves. ObPV inoculation led to a marked accumulation of H2O2 in the inoculated leaves. Therefore, the effect of H2O2 treatments on the expression of six tobamovirus-inducible FADs was also studied. The expression of these FADs was upregulated to different degrees by H2O2 that correlated with ObPV-inducibility of these FADs. These results underline the importance of further studies on the role of pepper FADs in pepper-tobamovirus interactions.

The effects of foliar application of melatonin on some physiological and biochemical characteristics and expression of fatty acid desaturase gene in pistachio seedlings (Pistacia vera L.) under freezing stress

ABSTRACT In this study, the impacts of exogenous melatonin on freezing stress mitigation in pistachio (Pistacia vera L.) seedlings (30-days old) were investigated. Our results showed that in pistachio seedlings under freezing stress antioxidant enzyme activity, malondialdehyde (MDA) hydrogen peroxide (H2O2), electrolyte leakage, chlorophyll degradation, proline and soluble sugar and γ-aminobutyric acid (GABA) content increased. Phenolic component, phenylalanine ammonia lyase (PAL) activity and the expression of fatty acid desaturase (FAD2) gene increased whilst ascorbate and glutathione concentration significantly decreased in comparison with control. In this research, application of melatonin significantly reduced the antioxidant enzyme activity, MDA, H2O2, chlorophyll degradation, GABA concentration, soluble sugar, and proline contents under stress condition. In addition electrolyte leakage, PAL activity and transcripts of FAD2 gene markedly decreased when the leaves of pistachio seedlings sprayed with melatonin. The results of this study showed that MEL could alleviate the oxidative damages induced by freezing stress and to maintain the structure and mobility of cell membrane in pistachio seedlings under stress conditions. Considering that MEL is an inexpensive and safe bio-stimulator, it seems that MEL is a potential candidate that could be applied used to increase the resistant pistachio trees against variety of biotic and abiotic stresses in the field conditions.

Effects of dietary supplementation with apple peel powder on the growth, blood and liver parameters, and transcriptome of genetically improved farmed tilapia (GIFT, Oreochromis niloticus).

High-density aquaculture and nutritional imbalances may promote fatty liver in genetically improved farmed tilapia (GIFT, Oreochromis niloticus), thus reducing the gains achieved by breeding. In this study, apple peel powder (APP) was used as a feed additive for GIFT. A control group (fed on a diet without APP) and five groups fed on diets supplemented with APP (at 0.05%, 0.1%, 0.2%, 0.4%, or 0.8% of the diet, by weight) were established to investigate the effects of APP on GIFT growth performance and physiological parameters, and on gene expression as determined by transcriptomic analysis. Dietary supplementation with APP at 0.2% promoted GIFT growth, reduced total cholesterol and triacylglycerol levels in the serum and liver, and decreased alanine aminotransferase and aspartate aminotransferase activities in the serum. Gene expression profiles in the liver were compared among the control, 0.2% APP, and 0.8% APP groups, and differentially expressed genes among these groups were identified. Annotation analyses using tools at the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases showed that the differentially expressed genes were mainly involved in the regulation of immunity and fat metabolism. The results showed that excessive supplementation with APP in the diet significantly inhibited the expression of insulin-like growth factor 2 and liver-type fatty acid-binding protein, and stimulated the expression of fatty acid desaturase 2, heat shock protein 90 beta family member 1, and nuclear factor kappa B. This resulted in disordered lipid metabolism and increased pro-inflammatory reactions, which in turn caused liver damage. Therefore, APP has good potential as an environmentally friendly feed additive for GIFT at levels of 0.1%–0.2% in the diet, but excessive amounts can have adverse effects.

Long-chain PUFA profiles in parental diets induce long-term effects on growth, fatty acid profiles, expression of fatty acid desaturase 2 and selected immune system-related genes in the offspring of gilthead seabream

The present study investigated the effects of nutritional programming through parental feeding on offspring performance and expression of selected genes related to stress resistance in a marine teleost. Gilthead seabream broodstock were fed diets containing various fish oil (FO)/vegetable oil ratios to determine their effects on offspring performance along embryogenesis, larval development and juvenile on-growing periods. Increased substitution of dietary FO by linseed oil (LO) up to 80 % LO significantly reduced the total number of eggs produced by kg per female per spawn. Moreover, at 30 d after hatching, parental feeding with increasing LO up to 80 % led to up-regulation of the fatty acyl desaturase 2 gene (fads2) that was correlated with the increase in conversion rates of related PUFA. Besides, cyclo-oxygenase 2 (cox2) and TNF-α (tnf-α) gene expression was also up-regulated by the increase in LO in broodstock diets up to 60 or 80 %, respectively. When 4-month-old offspring were challenged with diets having different levels of FO, the lowest growth was found in juveniles from broodstock fed 100 % FO. An increase in LO levels in the broodstock diet up to 60LO raised LC-PUFA levels in the juveniles, regardless of the juvenile's diet. The results showed that it is possible to nutritionally programme gilthead seabream offspring through the modification of the fatty acid profiles of parental diets to improve the growth performance of juveniles fed low FO diets, inducing long-term changes in PUFA metabolism with up-regulation of fads2 expression. The present study provided the first pieces of evidence of the up-regulation of immune system-related genes in the offspring of parents fed increased FO replacement by LO.