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Sample records for acid desaturase sfat-1-transgenic

  1. Efficient production of omega-3 fatty acid desaturase (sFat-1)-transgenic pigs by somatic cell nuclear transfer.

    PubMed

    Pan, DengKe; Zhang, Li; Zhou, YanRong; Feng, Chong; Long, Chuan; Liu, Xiao; Wan, Rong; Zhang, Jian; Lin, AiXing; Dong, EnQiu; Wang, ShuChen; Xu, HouGang; Chen, HongXing

    2010-04-01

    Omega-3(omega-3) fatty acid desaturase transgenic pigs may improve carcass fatty acid composition. The use of transgenic pigs is also an excellent large animal model for studying the role of omega-3 fatty acids in the prevention and treatment of coronary heart disease and cancer. Transgenic pigs carrying synthesized fatty acid desaturase-1 gene (sFat-1) from Caenorhabditis briggsae by somatic cell nuclear transfer (SCNT) were produced for the first time in China. Porcine fetal fibroblast cells were transfected with a sFat-1 expression cassette by the liposome-mediated method. Transgenic embryos were reconstructed by nuclear transfer of positive cells into enucleated in vitro matured oocytes. A total of 1889 reconstructed embryos were transferred into 10 naturally cycling gilts. Nine early pregnancies were established, 7 of which went to term. Twenty-one piglets were born. The cloning efficiency was 1.1% (born piglets/transferred embryos). The integration of the sFat-1 gene was confirmed in 15 live cloned piglets by PCR and Southern blot except for 2 piglets. Expression of the sFat-1 gene in 12 of 13 piglets was detected with RT-PCR. The data demonstrates that an efficient system for sFat-1 transgenic cloned pigs was developed, which led to the successful production of piglets expressing the sFat-1 gene.

  2. Rapid and Sensitive Detection of sFAT-1 Transgenic Pigs by Visual Loop-Mediated Isothermal Amplification.

    PubMed

    Tao, Chenyu; Yang, Yalan; Li, Xunbi; Zheng, Xinmin; Ren, Hongyan; Li, Kui; Zhou, Rong

    2016-07-01

    Genetically modified (GM) livestock have the potential to contribute to improving the environment and human health, with consumption of fewer resources and reduced waste production. However, the transgene process also poses risks. The safety assessment and control of transgenic animal products have drawn wide attention, and the relevant regulations and technology are being developed. Quick testing technology plays a significant role in on-site and customs sampling. Nowadays, loop-mediated isothermal amplification (LAMP) was widely applied in nucleic acid analysis because of its simplicity, rapidity, high efficiency and specificity. In this study, a specific, sensitive detection system for detecting sFAT-1 transgenic pigs was designed. A set of six primers including two loop primers was designed for the target sequence. The DNA samples were amplified in less than 1 h at the optimized temperature and detecting by both Nephelometer LA-320c and unaided eyes directly adding calcein. The detection limit of sFAT-1 LAMP was as low as 1.26 ng/μL. Furthermore, blind tests of transgenic and non-transgenic DNA samples were all correctly detected. Hence, the results in this study demonstrated that LAMP is a very useful tool for transgenic detection.

  3. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  4. Unsaturated fatty acids, desaturases, and human health.

    PubMed

    Lee, Hyungjae; Park, Woo Jung

    2014-02-01

    With the increasing concern for health and nutrition, dietary fat has attracted considerable attention. The composition of fatty acids in a diet is important since they are associated with major diseases, such as cancers, diabetes, and cardiovascular disease. The biosynthesis of unsaturated fatty acids (UFA) requires the expression of dietary fat-associated genes, such as SCD, FADS1, FADS2, and FADS3, which encode a variety of desaturases, to catalyze the addition of a double bond in a fatty acid chain. Recent studies using new molecular techniques and genomics, as well as clinical trials have shown that these genes and UFA are closely related to physiological conditions and chronic diseases; it was found that the existence of alternative transcripts of the desaturase genes and desaturase isoforms might affect human health and lipid metabolism in different ways. In this review, we provide an overview of UFA and desaturases associated with human health and nutrition. Moreover, recent findings of UFA, desaturases, and their associated genes in human systems are discussed. Consequently, this review may help elucidate the complicated physiology of UFA in human health and diseases.

  5. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    PubMed Central

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism. PMID:26742061

  6. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances.

    PubMed

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-04

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  7. Mutant fatty acid desaturase and methods for directed mutagenesis

    DOEpatents

    Shanklin, John; Whittle, Edward J.

    2008-01-29

    The present invention relates to methods for producing fatty acid desaturase mutants having a substantially increased activity towards substrates with fewer than 18 carbon atom chains relative to an unmutagenized precursor desaturase having an 18 carbon chain length specificity, the sequences encoding the desaturases and to the desaturases that are produced by the methods. The present invention further relates to a method for altering a function of a protein, including a fatty acid desaturase, through directed mutagenesis involving identifying candidate amino acid residues, producing a library of mutants of the protein by simultaneously randomizing all amino acid candidates, and selecting for mutants which exhibit the desired alteration of function. Candidate amino acids are identified by a combination of methods. Enzymatic, binding, structural and other functions of proteins can be altered by the method.

  8. Newly identified essential amino acid residues affecting ^8-sphingolipid desaturase activity revealed by site-directed mutagenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to identify amino acid residues crucial for the enzymatic activity of ^8-sphingolipid desaturases, a sequence comparison was performed among ^8-sphingolipid desaturases and ^6-fatty acid desaturase from various plants. In addition to the known conserved cytb5 (cytochrome b5) HPGG motif and...

  9. Co-expression of the borage Delta 6 desaturase and the Arabidopsis Delta 15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean.

    PubMed

    Eckert, Helene; La Vallee, Brad; Schweiger, Bruce J; Kinney, Anthony J; Cahoon, Edgar B; Clemente, Tom

    2006-10-01

    Two relatively rare fatty acids, gamma-linolenic acid (GLA) and stearidonic acid (STA), have attracted much interest due to their nutraceutical and pharmaceutical potential. STA, in particular, has been considered a valuable alternative source for omega-3 fatty acids due to its enhanced conversion efficiency in animals to eicosapentaenoic acid when compared with the more widely consumed omega-3 fatty acid, alpha-linolenic acid (ALA), present in most vegetable oils. Exploiting the wealth of information currently available on in planta oil biosynthesis and coupling this information with the tool of genetic engineering it is now feasible to deliberately perturb fatty acid pools to generate unique oils in commodity crops. In an attempt to maximize the STA content of soybean oil, a borage Delta(6) desaturase and an Arabidopsis Delta(15) desaturase were pyramided by either sexual crossing of transgenic events, re-transformation of a Delta(6) desaturase event with the Delta(15) desaturase or co-transformation of both desaturases. Expression of both desaturases in this study was under the control of the seed-specific soybean beta-conglycinin promoter. Soybean events that carried only the Delta(15 )desaturase possessed a significant elevation of ALA content, while events with both desaturases displayed a relative STA abundance greater than 29%, creating a soybean with omega-3 fatty acids representing over 60% of the fatty acid profile. Analyses of the membrane lipids in a subset of the transgenic events suggest that soybean seeds compensate for enhanced production of polyunsaturated fatty acids by increasing the relative content of palmitic acid in phosphatidylcholine and other phospholipids.

  10. Production of γ-linolenic acid and stearidonic acid by Synechococcus sp. PCC7002 containing cyanobacterial fatty acid desaturase genes

    NASA Astrophysics Data System (ADS)

    Dong, Xuewei; He, Qingfang; Peng, Zhenying; Yu, Jinhui; Bian, Fei; Li, Youzhi; Bi, Yuping

    2016-07-01

    Genetic modification is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. Synechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid (GLA) and stearidonic acid (SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6D, Syd15D and Syd6Dd15D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in Synechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.

  11. Molecular cloning and functional characterization of a Δ6-fatty acid desaturase gene from Rhizopus oryzae.

    PubMed

    Zhu, Yu; Zhang, Bi-Bo

    2013-09-01

    The objective was to screen for and isolate a novel enzyme with the specific activity of a Δ6-fatty acid desaturase from Rhizopus oryzae. In this study, R. oryzae was identified as a novel fungal species that produces large amounts of γ-linolenic acid. A full-length cDNA, designated here as RoD6D, with high homology to fungal Δ6-fatty acid desaturase genes was isolated from R. oryzae by using the rapid amplification of cDNA ends method. It had an open reading frame of 1176 bp encoding a deduced polypeptide of 391 amino acids. Bioinformatics analysis characterized the putative RoD6D protein as a typical membrane-bound desaturase, including three conserved histidine-rich motifs, a hydropathy profile, and a cytochrome b5 -like domain in the N terminus. When the coding sequence was expressed in the Saccharomyces cerevisiae strain INVScl, the encoded product of RoD6D exhibited Δ6-fatty acid desaturase activity that led to the accumulation of γ-linolenic acid. The corresponding genomic sequence of RoD6D was 1565 bp in length, with five introns. This is the first report on the characterization and gene cloning of a Δ6-fatty acid desaturase of R. oryzae from Douchi.

  12. Oxygen induction of a novel fatty acid n-6 desaturase in the soil protozoon, Acanthamoeba castellanii.

    PubMed Central

    Rutter, Andrew J; Thomas, Katie L; Herbert, Derek; Henderson, R James; Lloyd, David; Harwood, John L

    2002-01-01

    Induction of fatty acid desaturation is very important for the temperature adaptation of poikilotherms. However, in oxygen-limited late-exponential-phase Acanthamoeba castellanii cultures, oxygen alone was able to induce increased activity of a fatty acid desaturase that converts oleate into linoleate and which has been implicated in the temperature adaptation of this organism. Experiments with Delta(10)-nonadecenoate showed that the enzyme is an n -6 desaturase rather than a Delta(12)-desaturase. It also used preferentially 1-acyl-2-oleoyl-phosphatidylcholine as substrate and NAD(P)H as electron donor. The involvement of cytochrome b (5) as an intermediate electron carrier was shown by difference spectra measurements and anti-(cytochrome b (5)) antibody experiments. Of the three protein components of the desaturase complex, oxygen only increased the activity of the terminal (cyanide-sensitive) protein during n -6 desaturase induction. The induction of this terminal protein paralleled well the increase in overall oleate n -6 desaturation. The ability of oxygen to induce oleate desaturase independently of temperature in this lower eukaryotic animal model is of novel intrinsic interest, as well as being important for the design of future experiments to determine the molecular mechanism of temperature adaptation in poikilotherms. PMID:12153399

  13. Functional and safety evaluation of transgenic pork rich in omega-3 fatty acids.

    PubMed

    Tang, Maoxue; Qian, Lili; Jiang, Shengwang; Zhang, Jian; Song, Pengkun; Chen, Yaoxing; Cui, Wentao; Li, Kui

    2014-08-01

    Genetically modified animals rich in omega-3 unsaturated fatty acid offer a new strategy to improve the human health, but at the same time present a challenge in terms of food safety assessment. In this study, we evaluated the function and safety of sFat-1 transgenic pork rich in omega-3 fatty acids in mice by feeding basic diet and diets that contain wild type pork and sFat-1 transgenic pork. Blood biochemistry, haematology, peripheral T cell distributions, bacterial counts, gross necropsy, histopathology and organ weights were performed in mice fed with different doses of wild type and transgenic pork. Results indicated that both low and high dose of wild type and transgenic pork had no significant effect on blood biochemistry, T cell distribution, immunoglobulins and bacterial counts in intestine and feces. However, it was noted that both low and high dose of transgenic pork improved the liver immune system in mice, which is probably due to the beneficial contribution of high level of the "good" fatty acids in transgenic pork. There is no significant effect of transgenic pork on all other organs in mice. In summary, our study clearly demonstrated that feeding transgenic pork rich in omega-3 fatty acids did not cause any harm to mice, and in fact, improved the liver immune system.

  14. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco

    SciTech Connect

    Cahoon, E.B.; Shanklin, J.; Ohlrogge, J.B. )

    1992-12-01

    Little is known about the metabolic origin of petroselinic acid (18:1[Delta][sup 6cis]), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the [Delta][sup 9]-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and [Delta][sup 4]-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase. 27 refs., 5 figs.

  15. Fatty acid desaturase gene variants, cardiovascular risk factors, and myocardial infarction in the costa rica study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variation in fatty acid desaturases (FADS) has previously been linked to long-chain polyunsaturated fatty acids (PUFAs) in adipose tissue and cardiovascular risk. The goal of our study was to test associations between six common FADS polymorphisms (rs174556, rs3834458, rs174570, rs2524299, r...

  16. INHIBITION OF FATTY ACID DESATURASES IN Drosophila melanogaster LARVAE BLOCKS FEEDING AND DEVELOPMENTAL PROGRESSION.

    PubMed

    Wang, Yiwen; da Cruz, Tina Correia; Pulfemuller, Alicia; Grégoire, Stéphane; Ferveur, Jean-François; Moussian, Bernard

    2016-05-01

    Fatty acid desaturases are metabolic setscrews. To study their systemic impact on growth in Drosophila melanogaster, we inhibited fatty acid desaturases using the inhibitor CAY10566. As expected, the amount of desaturated lipids is reduced in larvae fed with CAY10566. These animals cease feeding soon after hatching, and their growth is strongly attenuated. A starvation program is not launched, but the expression of distinct metabolic genes is activated, possibly to mobilize storage material. Without attaining the normal size, inhibitor-fed larvae molt to the next stage indicating that the steroid hormone ecdysone triggers molting correctly. Nevertheless, after molting, expression of ecdysone-dependent regulators is not induced. While control larvae molt a second time, these larvae fail to do so and die after few days of straying. These effects are similar to those observed in experiments using larvae deficient for the fatty acid desaturase1 gene. Based on these data, we propose that the ratio of saturated to unsaturated fatty acids adjusts a sensor system that directs feeding behavior. We also hypothesize that loss of fatty acid desaturase activity leads to a block of the genetic program of development progression indirectly by switching on a metabolic compensation program.

  17. Inventory of Fatty Acid Desaturases in the Pennate Diatom Phaeodactylum tricornutum

    PubMed Central

    Dolch, Lina-Juana; Maréchal, Eric

    2015-01-01

    The diatom Phaeodactylum is rich in very long chain polyunsaturated fatty acids (PUFAs). Fatty acid (FA) synthesis, elongation, and desaturation have been studied in depth in plants including Arabidopsis, but for secondary endosymbionts the full picture remains unclear. FAs are synthesized up to a chain length of 18 carbons inside chloroplasts, where they can be incorporated into glycerolipids. They are also exported to the ER for phospho- and betaine lipid syntheses. Elongation of FAs up to 22 carbons occurs in the ER. PUFAs can be reimported into plastids to serve as precursors for glycerolipids. In both organelles, FA desaturases are present, introducing double bonds between carbon atoms and giving rise to a variety of molecular species. In addition to the four desaturases characterized in Phaeodactylum (FAD2, FAD6, PtD5, PtD6), we identified eight putative desaturase genes. Combining subcellular localization predictions and comparisons with desaturases from other organisms like Arabidopsis, we propose a scheme at the whole cell level, including features that are likely specific to secondary endosymbionts. PMID:25786062

  18. Effect of maternal micronutrients (folic acid, vitamin B12) and omega 3 fatty acids on liver fatty acid desaturases and transport proteins in Wistar rats.

    PubMed

    Wadhwani, Nisha S; Manglekar, Rupali R; Dangat, Kamini D; Kulkarni, Asmita V; Joshi, Sadhana R

    2012-01-01

    A disturbed fatty acid metabolism increases the risk of adult non-communicable diseases. This study examines the effect of maternal micronutrients on the fatty acid composition, desaturase activity, mRNA levels of fatty acid desaturases and transport proteins in the liver. Pregnant female rats were divided into 6 groups at 2 levels of folic acid both in the presence and absence of vitamin B(12). The vitamin B(12) deficient groups were supplemented with omega 3 fatty acid. An imbalance of maternal micronutrients reduces liver docosahexaenoic acid, increases Δ5 desaturase activity but decreases mRNA levels, decreases Δ6 desaturase activity but not mRNA levels as compared to control. mRNA level of Δ5 desaturase reverts back to the levels of the control group as a result of omega 3 fatty acid supplementation. Our data for the first time indicates that maternal micronutrients differentially alter the activity and expression of fatty acid desaturases in the liver.

  19. Linoleic acid biosynthesis and characterization of the. Delta. sup 12 desaturase in insects

    SciTech Connect

    Cripps, C.

    1988-01-01

    De novo biosynthesis of linoleic acid was demonstrated in vivo in 8 of 32 insect species examined, including both holometabolous and hemimetabolous species. The incorporation of (1-{sup 14}C) acetate into linoleic acid was demonstrated by radio-gas-liquid chromatography (radio-GLC), and in selected species by radio-high-performance liquid chromatography, silver nitrate thin-layer chromatography, radio-GLC and GLC linked to mass spectrometry of ozonolysis products. Analysis of the ozonolysis products clearly demonstrated that the entire molecule was labeled and that synthesis of linoleate was de novo from acetate. The in vivo incorporation of (1-{sup 14}C)acetate into lipid was monitored during the final three stadia of both male and female house crickets, Acheta domesticus. Characterization of the {Delta}{sup 12}-desaturase showed that, in the house cricket, this enzyme is microsomal and requires a reduced pyridine dinucleotide as a cofactor, with NADPH the preferred electron donor. The optimal substrate concentration for desaturation is about 40 uM. Addition of the microsomal supernatant, MgCl{sub 2} or ATP did not enhance activity. The form of the substrate for the desaturase, oleic acid, was determined and appears to be a CoA derivative, as is true for most animal desaturases, rather than a complex lipid, as it is in plants.

  20. Polyunsaturated fatty acid supplementation reverses cystic fibrosis-related fatty acid abnormalities in CFTR-/- mice by suppressing fatty acid desaturases.

    PubMed

    Njoroge, Sarah W; Laposata, Michael; Boyd, Kelli L; Seegmiller, Adam C

    2015-01-01

    Cystic fibrosis patients and model systems exhibit consistent abnormalities in metabolism of polyunsaturated fatty acids that appear to play a role in disease pathophysiology. Recent in vitro studies have suggested that these changes are due to overexpression of fatty acid desaturases that can be reversed by supplementation with the long-chain polyunsaturated fatty acids docosahexaenoate and eicosapentaenoate. However, these findings have not been tested in vivo. The current study aimed to test these results in an in vivo model system, the CFTR(-/-) knockout mouse. When compared with wild-type mice, the knockout mice exhibited fatty acid abnormalities similar to those seen in cystic fibrosis patients and other model systems. The abnormalities were confined to lung, ileum and pancreas, tissues that are affected by the disease. Similar to in vitro models, these fatty acid changes correlated with increased expression of Δ5- and Δ6-desaturases and elongase 5. Dietary supplementation with high-dose free docosahexaenoate or a combination of lower-dose docosahexaenoate and eicosapentaenoate in triglyceride form corrected the fatty acid abnormalities and reduced expression of the desaturase and elongase genes in the ileum and liver of knockout mice. Only the high-dose docosahexaenoate reduced histologic evidence of disease, reducing mucus accumulation in ileal sections. These results provide in vivo support for the hypothesis that fatty acid abnormalities in cystic fibrosis result from abnormal expression and activity of metabolic enzymes in affected cell types. They further demonstrate that these changes can be reversed by dietary n-3 fatty acid supplementation, highlighting the potential therapeutic benefit for cystic fibrosis patients.

  1. Possible involvement of delta-6-desaturase in control of melanoma growth by gamma-linolenic acid.

    PubMed

    Gardiner, N S; Duncan, J R

    1991-03-01

    This study examined the effects of linoleic acid (LA) and gamma-linolenic acid (GLA) on BL6 melanoma growth in cell culture and of safflower oil (SFO) which contains LA and evening primrose oil (EPO) which contains GLA, on melanoma growth when grown in mice. The delta-6-desaturase activity of the melanoma cells in the two systems was also examined and an attempt made to relate the activity of the enzyme to the effects of GLA on cell and tumour growth. LA and GLA were found to be equipotent in inhibiting growth of the in vitro cultured BL6 cells which were found to contain an appreciable level of delta-6-desaturase activity. EPO was however found to be a more potent promoter of in vivo melanoma growth in mice than SFO. Melanomas grown in mice were found to lack delta-6-desaturase activity suggesting that the EPO diet, by providing GLA, was able to compensate for the loss of enzyme activity in the melanomas. The possibility that melanomas in mice have a requirement for GLA for growth while in in vitro cultured cells excess GLA inhibits the growth of the cells through an increase in lipid peroxidation is discussed.

  2. Expression of a cyanobacterial {del}{sup 6}-desaturase gene results in {gamma}-linolenic acid production in transgenic plants

    SciTech Connect

    Reddy, A.S.; Thomas, T.L.

    1996-05-01

    Gamma-linolenic acid (GLA), a nutritionally important fatty acid in human and animal diets, is not produced in oil seed crops. Many oil seed plants, however, produce significant quantities of linoleic acid, a fatty acid that could be converted to GLA by the enzyme {del}{sup 6}-desaturase if it were present. As a first step to producing GLA in oil seed crops, we have cloned a cyanobacterial {del}{sup 6}-desaturase gene. Expression of this gene in transgenic tobacco resulted in GLA accumulation. Octadecatetraenoic acid, a highly unsaturated, industrially important fatty acid, was also found in transgenic tobacco plants expressing the cyanobacterial {del}{sup 6}-desaturase. This is the first example of engineering the production of `novel` polyunsaturated fatty acids in transgenic plants. 28 refs., 4 figs., 1 tab.

  3. Maternal micronutrients and omega 3 fatty acids affect placental fatty acid desaturases and transport proteins in Wistar rats.

    PubMed

    Wadhwani, Nisha S; Dangat, Kamini D; Joshi, Asmita A; Joshi, Sadhana R

    2013-03-01

    Adequate supply of LCPUFA from maternal plasma is crucial for fetal normal growth and development. The present study examines the effect of maternal micronutrients (folic acid and vitamin B12) and omega 3 fatty acids on placental mRNA levels of fatty acid desaturases (Δ5 and Δ6) and transport proteins. Pregnant female rats were divided into 6 groups at 2 levels of folic acid both in the presence and absence of vitamin B12. Both the vitamin B12 deficient groups were supplemented with omega 3 fatty acid. Maternal vitamin B12 deficiency reduced placental mRNA and protein levels of Δ5 desaturase, mRNA levels of FATP1 and FATP4 (p<0.05 for all) as compared to control while omega 3 fatty acid supplementation normalized the levels. Our data for the first time indicates that altered maternal micronutrients and omega 3 fatty acids play a key role in regulating fatty acid desaturase and transport protein expression in placenta.

  4. Δ12-Fatty Acid Desaturase from Candida parapsilosis Is a Multifunctional Desaturase Producing a Range of Polyunsaturated and Hydroxylated Fatty Acids

    PubMed Central

    Buček, Aleš; Matoušková, Petra; Sychrová, Hana; Pichová, Iva; Hrušková-Heidingsfeldová, Olga

    2014-01-01

    Numerous Δ12-, Δ15- and multifunctional membrane fatty acid desaturases (FADs) have been identified in fungi, revealing great variability in the enzymatic specificities of FADs involved in biosynthesis of polyunsaturated fatty acids (PUFAs). Here, we report gene isolation and characterization of novel Δ12/Δ15- and Δ15-FADs named CpFad2 and CpFad3, respectively, from the opportunistic pathogenic yeast Candida parapsilosis. Overexpression of CpFad3 in Saccharomyces cerevisiae strains supplemented with linoleic acid (Δ9,Δ12-18:2) and hexadecadienoic acid (Δ9,Δ12-16:2) leads to accumulation of Δ15-PUFAs, i.e., α-linolenic acid (Δ9,Δ12,Δ15-18:3) and hexadecatrienoic acid with an unusual terminal double bond (Δ9,Δ12,Δ15-16:3). CpFad2 produces a range of Δ12- and Δ15-PUFAs. The major products of CpFad2 are linoleic and hexadecadienoic acid (Δ9,Δ12-16:2), accompanied by α-linolenic acid and hexadecatrienoic acid (Δ9,Δ12,Δ15-16:3). Using GC/MS analysis of trimethylsilyl derivatives, we identified ricinoleic acid (12-hydroxy-9-octadecenoic acid) as an additional product of CpFad2. These results demonstrate that CpFAD2 is a multifunctional FAD and indicate that detailed analysis of fatty acid derivatives might uncover a range of enzymatic selectivities in other Δ12-FADs from budding yeasts (Ascomycota: Saccharomycotina). PMID:24681902

  5. Molecular Cloning and Functional Expression of a Δ9- Fatty Acid Desaturase from an Antarctic Pseudomonas sp. A3

    PubMed Central

    Garba, Lawal; Mohamad Ali, Mohd Shukuri; Oslan, Siti Nurbaya; Rahman, Raja Noor Zaliha Raja Abd

    2016-01-01

    Fatty acid desaturase enzymes play an essential role in the synthesis of unsaturated fatty acids. Pseudomonas sp. A3 was found to produce a large amount of palmitoleic and oleic acids after incubation at low temperatures. Using polymerase Chain Reaction (PCR), a novel Δ9- fatty acid desaturase gene was isolated, cloned, and successfully expressed in Escherichia coli. The gene was designated as PA3FAD9 and has an open reading frame of 1,185 bp which codes for 394 amino acids with a predicted molecular weight of 45 kDa. The activity of the gene product was confirmed via GCMS, which showed a functional putative Δ9-fatty acid desaturase capable of increasing the total amount of cellular unsaturated fatty acids of the E. coli cells expressing the gene. The results demonstrate that the cellular palmitoleic acids have increased two-fold upon expression at 15°C using only 0.1 mM IPTG. Therefore, PA3FAD9 from Pseudomonas sp.A3 codes for a Δ9-fatty acid desaturase-like protein which was actively expressed in E. coli. PMID:27494717

  6. Amino Acid Change in an Orchid Desaturase Enables Mimicry of the Pollinator’s Sex Pheromone

    DOE PAGES

    Sedeek, Khalid E. M.; Whittle, Edward; Guthörl, Daniela; ...

    2016-05-19

    Here, we show that mimicry illustrates the power of selection to produce phenotypic convergence in biology. A striking example is the imitation of female insects by plants that are pollinated by sexual deception of males of the same insect species. This involves mimicry of visual, tactile, and chemical signals of females, especially their sex pheromones. The Mediterranean orchid Ophrys exaltata employs chemical mimicry of cuticular hydrocarbons, particularly the 7-alkenes, in an insect sex pheromone to attract and elicit mating behavior in its pollinators, males of the cellophane bee Colletes cunicularius. A difference in alkene double-bond positions is responsible for reproductivemore » isolation between O. exaltata and closely related species, such as O. sphegodes. We show that these 7-alkenes are likely determined by the action of the stearoyl-acyl-carrier-protein desaturase (SAD) homolog SAD5. After gene duplication, changes in subcellular localization relative to the ancestral housekeeping desaturase may have allowed proto-SAD5’s reaction products to undergo further biosynthesis to both 7- and 9-alkenes. Such ancestral coproduction of two alkene classes may have led to pollinator-mediated deleterious pleiotropy. Despite possible evolutionary intermediates with reduced activity, amino acid changes at the bottom of the substrate-binding cavity have conferred enzyme specificity for 7-alkene biosynthesis by preventing the binding of longer-chained fatty acid (FA) precursors by the enzyme. In conclusion, this change in desaturase function enabled the orchid to perfect its chemical mimicry of pollinator sex pheromones by escape from deleterious pleiotropy, supporting a role of pleiotropy in determining the possible trajectories of adaptive evolution.« less

  7. Amino Acid Change in an Orchid Desaturase Enables Mimicry of the Pollinator’s Sex Pheromone

    SciTech Connect

    Sedeek, Khalid E. M.; Whittle, Edward; Guthörl, Daniela; Grossniklaus, Ueli; Shanklin, John; Schlüter, Philipp M.

    2016-05-19

    Here, we show that mimicry illustrates the power of selection to produce phenotypic convergence in biology. A striking example is the imitation of female insects by plants that are pollinated by sexual deception of males of the same insect species. This involves mimicry of visual, tactile, and chemical signals of females, especially their sex pheromones. The Mediterranean orchid Ophrys exaltata employs chemical mimicry of cuticular hydrocarbons, particularly the 7-alkenes, in an insect sex pheromone to attract and elicit mating behavior in its pollinators, males of the cellophane bee Colletes cunicularius. A difference in alkene double-bond positions is responsible for reproductive isolation between O. exaltata and closely related species, such as O. sphegodes. We show that these 7-alkenes are likely determined by the action of the stearoyl-acyl-carrier-protein desaturase (SAD) homolog SAD5. After gene duplication, changes in subcellular localization relative to the ancestral housekeeping desaturase may have allowed proto-SAD5’s reaction products to undergo further biosynthesis to both 7- and 9-alkenes. Such ancestral coproduction of two alkene classes may have led to pollinator-mediated deleterious pleiotropy. Despite possible evolutionary intermediates with reduced activity, amino acid changes at the bottom of the substrate-binding cavity have conferred enzyme specificity for 7-alkene biosynthesis by preventing the binding of longer-chained fatty acid (FA) precursors by the enzyme. In conclusion, this change in desaturase function enabled the orchid to perfect its chemical mimicry of pollinator sex pheromones by escape from deleterious pleiotropy, supporting a role of pleiotropy in determining the possible trajectories of adaptive evolution.

  8. Enzymatic modification by point mutation and functional analysis of an omega-6 fatty acid desaturase from Arctic Chlamydomonas sp.

    PubMed

    Jung, Woongsic; Kim, Eun Jae; Han, Se Jong; Kang, Sung-Ho; Choi, Han-Gu; Kim, Sanghee

    2017-02-07

    Arctic Chlamydomonas sp. is a dominant microalgal strain in cold or frozen freshwater in the Arctic region. The full-length open reading frame of the omega-6 fatty acid desaturase gene (AChFAD6) was obtained from the transcriptomic database of Arctic Chlamydomonas sp. from the KOPRI culture collection of polar micro-organisms. Amino acid sequence analysis indicated the presence of three conserved histidine-rich segments as unique characteristics of omega-6 fatty acid desaturases, and three transmembrane regions transported to plastidic membranes by chloroplast transit peptides in the N-terminal region. The AChFAD6 desaturase activity was examined by expressing wild-type and V254A mutant (Mut-AChFAD6) heterologous recombinant proteins. Quantitative gas chromatography indicated that the concentration of linoleic acids in AChFAD6-transformed cells increased more than 3-fold [6.73 ± 0.13 mg g(-1) dry cell weight (DCW)] compared with cells transformed with vector alone. In contrast, transformation with Mut-AChFAD6 increased the concentration of oleic acid to 9.23 ± 0.18 mg g(-1) DCW, indicating a change in enzymatic activity to mimic that of stearoyl-CoA desaturase. These results demonstrate that AChFAD6 of Arctic Chlamydomonas sp. increases membrane fluidity by enhancing denaturation of C18 fatty acids and facilitates production of large quantities of linoleic fatty acids in prokaryotic expression systems.

  9. Bioinformatics study of delta-12 fatty acid desaturase 2 (FAD2) gene in oilseeds.

    PubMed

    Dehghan Nayeri, Fatemeh; Yarizade, Kazem

    2014-08-01

    Fatty acid desaturases constitute a group of enzymes that introduce double bonds into the hydrocarbon chains of fatty acids to produce unsaturated fatty acids. In plants, seed-specific delta-12 fatty acid desaturase 2 (FAD2) is responsible for the high content of linoleic acid by inserting a double bond at the delta-12 (omega-6) position of oleic acid. In this study, sixteen FAD2 and FAD2-2 protein sequences from oilseeds were analyzed by computational tools including two databases of the NCBI and EXPASY and data management tools such as SignalP, TMHMM, Psort, ProtParam, TargetP, PLACE and PlantCARE. These services were used to predict the protein properties such as molecular mass, pI, signal peptide, transmembrane and conserved domains, secondary and spatial structures. The polypeptide sequences were aligned and a neighbour-joining tree was constructed using MEGA5.1 to elucidate phylogenetic relationships among FAD2 genes. Based on the phylogenetic analysis species with high similarity in FAD2 sequence grouped together. FAD2 proteins include highly conserved histidine-rich motifs (HECGHH, HRRHH and HV[A/C/T]HH) that are located by three to five transmembrane anchors. For further investigations Sesamum indicum FAD2 was selected and analyzed by bioinformatics tools. Analysis showed no N-terminal signal peptide for probable localization of FAD2 protein in cytoplasmic organelles such as chloroplast, mitochondria and Golgi. Instead the C-terminal signaling motif YNNKL, Y(K/N)NKF or YRNKI allows FAD2 protein to selectively bind to and embed in the endoplasmic reticulum. FAD2 promoter contains different cis-regulatory elements involve in the biotic and abiotic stresses response or control of gene expression specifically in seeds.

  10. Exploring the biosynthesis of unsaturated fatty acids in Bacillus cereus ATCC 14579 and functional characterization of novel acyl-lipid desaturases.

    PubMed

    Chazarreta Cifré, Lorena; Alemany, Mariana; de Mendoza, Diego; Altabe, Silvia

    2013-10-01

    At low temperatures, Bacillus cereus synthesizes large amounts of unsaturated fatty acids (UFAs) with double bonds in positions Δ5 and Δ10, as well as Δ5,10 diunsaturated fatty acids. Through sequence homology searches, we identified two open reading frames (ORFs) encoding a putative Δ5 desaturase and a fatty acid acyl-lipid desaturase in the B. cereus ATCC 14579 genome, and these were named BC2983 and BC0400, respectively. Functional characterization of ORFs BC2983 and BC0400 by means of heterologous expression in Bacillus subtilis confirmed that they both encode acyl-lipid desaturases that use phospholipids as the substrates and have Δ5 and Δ10 desaturase activities. Thus, these ORFs were correspondingly named desA (Δ5 desaturase) and desB (Δ10 desaturase). We established that DesA utilizes ferredoxin and flavodoxins (Flds) as electron donors for the desaturation reaction, while DesB preferably employs Flds. In addition, increased amounts of UFAs were found when B. subtilis expressing B. cereus desaturases was subjected to a cold shock treatment, indicating that the activity or the expression of these enzymes is upregulated in response to a decrease in growth temperature. This represents the first work reporting the functional characterization of fatty acid desaturases from B. cereus.

  11. Unexpected functional diversity in the fatty acid desaturases of the flour beetle Tribolium castaneum and identification of key residues determining activity.

    PubMed

    Haritos, Victoria S; Horne, Irene; Damcevski, Katherine; Glover, Karen; Gibb, Nerida

    2014-08-01

    Desaturases catalyse modifications to fatty acids which are essential to homeostasis and for pheromone and defensive chemical production. All desaturases of the flour beetle Tribolium castaneum were investigated via query of the sequenced genome which yielded 15 putative acyl-Coenzyme A genes. Eleven desaturase mRNA were obtained in full length and functionally expressed in yeast. Phylogenetic analysis separated the desaturases into 4 distinct clades; one clade contained conserved beetle Δ9 desaturases, second clade was Tribolium-specific having diverse activities including Δ5, Δ9 and Δ12 desaturation and the other 2 clades had mixed insect representatives. Three members of this clade contained unusual inserted sequences of ∼20 residues in the C-terminal region and were related to desaturases that all contained similar inserts. Deletion of the entirety of the insert in the flour beetle Δ12 desaturase abolished its activity but this was partially restored by the reintroduction of two histidine residues, suggesting the histidine(s) are required for activity but the full length insert is not. Five new desaturase activities were discovered: Δ9 desaturation of C12:0-C16:0 substrates; two unprecedented Δ5 enzymes acting on C18:0 and C16:0; Δ9 activity exclusively on C16:0 and a further stearate Δ9 desaturase. qPCR analysis ruled out a role in sex pheromone synthesis for the Δ5 and Δ9/C16:0 desaturases. The flour beetle genome has underpinned an examination of all transcribed desaturases in the organism and revealed a diversity of novel and unusual activities, an improved understanding of the evolutionary relationships among insect desaturases and sequence determinants of activity.

  12. Soybean plastidal omega-3 fatty acid desaturase genes GmFAD7 and GmFAD8: structure and expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomic structure and deduced protein sequence of soybean FAD7 and FAD8 have features similar to higher plant plastidal '-3 desaturases: 8 exons and 7 introns, predicted proteins of 453 amino acid residues containing three conserved histidine motifs, amino terminal chloroplast transit peptides, ...

  13. Delta 5 fatty acid desaturase upregulates the synthesis of polyunsaturated fatty acids in the marine diatom Phaeodactylum tricornutum.

    PubMed

    Peng, Kun-Tao; Zheng, Cun-Ni; Xue, Jiao; Chen, Xiao-Yan; Yang, Wei-Dong; Liu, Jie-Sheng; Bai, Weibin; Li, Hong-Ye

    2014-09-03

    Microalgae are important primary producers in the marine ecosystem and excellent sources of lipids and other bioactive compounds. The marine diatom Phaeodactylum tricornutum accumulates eicosapentaenoic acid (EPA, 20:5n-3) as its major component of fatty acids. To improve the EPA production, delta 5 desaturase, which plays a role in EPA biosynthetic pathway, was characterized in P. tricornutum. An annotated delta 5 desaturase PtD5b gene was cloned and overexpressed in P. tricornutum. The transgene was integrated into the genome demonstrated by Southern blot, and the overexpression of PtD5b was verified by qPCR and Western blot analysis. Fatty acid composition exhibited a significant increase in the unsaturated fatty acids. Monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) showed an increase of 75% and 64%, respectively. In particular, EPA showed an increase of 58% in engineered microalgae. Meanwhile, neutral lipid content showed an increase up to 65% in engineered microalgae. More importantly, engineered cells showed a similar growth rate with the wild type, thus keeping high biomass productivity. This work provides an effective way to improve the production of microalgal value-added bioproducts by metabolic engineering.

  14. Molecular analysis of a bifunctional fatty acid conjugase/desaturase from tung. Implications for the evolution of plant fatty acid diversity.

    PubMed

    Dyer, John M; Chapital, Dorselyn C; Kuan, Jui-Chang W; Mullen, Robert T; Turner, Charlotta; McKeon, Thomas A; Pepperman, Armand B

    2002-12-01

    The seed oil derived from the tung (Aleurites fordii Hemsl.) tree contains approximately 80% alpha-eleostearic acid (18:3delta(9cis,11trans,13trans)), an unusual conjugated fatty acid that imparts industrially important drying qualities to tung oil. Here, we describe the cloning and functional analysis of two closely related Delta(12) oleate desaturase-like enzymes that constitute consecutive steps in the biosynthetic pathway of eleostearic acid. Polymerase chain reaction screening of a tung seed cDNA library using degenerate oligonucleotide primers resulted in identification of two desaturases, FAD2 and FADX, that shared 73% amino acid identity. Both enzymes were localized to the endoplasmic reticulum of tobacco (Nicotiana tabacum cv Bright-Yellow 2) cells, and reverse transcriptase-polymerase chain reaction revealed that FADX was expressed exclusively within developing tung seeds. Expression of the cDNAs encoding these enzymes in yeast (Saccharomyces cerevisiae) revealed that FAD2 converted oleic acid (18:1delta(9cis)) into linoleic acid (18:2delta(9cis,12cis)) and that FADX converted linoleic acid into alpha-eleostearic acid. Additional characterization revealed that FADX exhibited remarkable enzymatic plasticity, capable of generating a variety of alternative conjugated and delta(12)-desaturated fatty acid products in yeast cells cultured in the presence of exogenously supplied fatty acid substrates. Unlike other desaturases reported to date, the double bond introduced by FADX during fatty acid desaturation was in the trans, rather than cis, configuration. Phylogenetic analysis revealed that tung FADX is grouped with delta(12) fatty acid desaturases and hydroxylases rather than conjugases, which is consistent with its desaturase activity. Comparison of FADX and other lipid-modifying enzymes (desaturase, hydroxylase, epoxygenase, acetylenase, and conjugase) revealed several amino acid positions near the active site that may be important determinants of enzymatic

  15. A Δ-9 Fatty Acid Desaturase Gene in the Microalga Myrmecia incisa Reisigl: Cloning and Functional Analysis.

    PubMed

    Xue, Wen-Bin; Liu, Fan; Sun, Zheng; Zhou, Zhi-Gang

    2016-07-16

    The green alga Myrmecia incisa is one of the richest natural sources of arachidonic acid (ArA). To better understand the regulation of ArA biosynthesis in M. incisa, a novel gene putatively encoding the Δ9 fatty acid desaturase (FAD) was cloned and characterized for the first time. Rapid-amplification of cDNA ends (RACE) was employed to yield a full length cDNA designated as MiΔ9FAD, which is 2442 bp long in sequence. Comparing cDNA open reading frame (ORF) sequence to genomic sequence indicated that there are 8 introns interrupting the coding region. The deduced MiΔ9FAD protein is composed of 432 amino acids. It is soluble and localized in the chloroplast, as evidenced by the absence of transmembrane domains as well as the presence of a 61-amino acid chloroplast transit peptide. Multiple sequence alignment of amino acids revealed two conserved histidine-rich motifs, typical for Δ9 acyl-acyl carrier protein (ACP) desaturases. To determine the function of MiΔ9FAD, the gene was heterologously expressed in a Saccharomyces cerevisiae mutant strain with impaired desaturase activity. Results of GC-MS analysis indicated that MiΔ9FAD was able to restore the synthesis of monounsaturated fatty acids, generating palmitoleic acid and oleic acid through the addition of a double bond in the Δ9 position of palmitic acid and stearic acid, respectively.

  16. A Δ-9 Fatty Acid Desaturase Gene in the Microalga Myrmecia incisa Reisigl: Cloning and Functional Analysis

    PubMed Central

    Xue, Wen-Bin; Liu, Fan; Sun, Zheng; Zhou, Zhi-Gang

    2016-01-01

    The green alga Myrmecia incisa is one of the richest natural sources of arachidonic acid (ArA). To better understand the regulation of ArA biosynthesis in M. incisa, a novel gene putatively encoding the Δ9 fatty acid desaturase (FAD) was cloned and characterized for the first time. Rapid-amplification of cDNA ends (RACE) was employed to yield a full length cDNA designated as MiΔ9FAD, which is 2442 bp long in sequence. Comparing cDNA open reading frame (ORF) sequence to genomic sequence indicated that there are 8 introns interrupting the coding region. The deduced MiΔ9FAD protein is composed of 432 amino acids. It is soluble and localized in the chloroplast, as evidenced by the absence of transmembrane domains as well as the presence of a 61-amino acid chloroplast transit peptide. Multiple sequence alignment of amino acids revealed two conserved histidine-rich motifs, typical for Δ9 acyl-acyl carrier protein (ACP) desaturases. To determine the function of MiΔ9FAD, the gene was heterologously expressed in a Saccharomyces cerevisiae mutant strain with impaired desaturase activity. Results of GC-MS analysis indicated that MiΔ9FAD was able to restore the synthesis of monounsaturated fatty acids, generating palmitoleic acid and oleic acid through the addition of a double bond in the Δ9 position of palmitic acid and stearic acid, respectively. PMID:27438826

  17. Delta-6 desaturase from borage converts linoleic acid to gamma-linolenic acid in HEK293 cells.

    PubMed

    Chen, Qing; Nimal, Jonathan; Li, Wanli; Liu, Xia; Cao, Wenguang

    2011-07-08

    Gamma-linolenic acid (GLA, 18:3 n6) is an essential polyunsaturated fatty acid of the omega-6 family and is found to be effective in prevention and/or treatment of various health problems. In this study, we evaluated the possibility of increasing γ-linolenic acid contents in mammalian cells using the delta-6 gene from Borago officinalis. The borage Δ6-desaturase gene (sDelta-6) was codon-optimized and introduced into HEK293 cells by lipofectin transfection. Co-expression of GFP with sDelta-6 and RT-PCR analysis indicated that sDelta-6 could be expressed in mammalian cells. Subsequently, the heterologous expression of borage Δ6-desaturase was evaluated by fatty acid analysis. Total cellular lipid analysis of transformed cells fed with linoleic acid (LA 18:2 n6) as a substrate showed that the expression of sDelta-6 resulted in an 228-483% (p<0.05) increase of GLA when compared with that in the control cells. The highest conversion efficiency of LA into GLA in sDelta-6(+) cells was 6.9 times higher than that in the control group (11.59% vs. 1.69%; p<0.05). Our present work demonstrated that the sDelta-6 gene from borage could be functionally expressed in mammalian cells, and could convert LA into GLA. Furthermore, this study may pave the way to generate transgenic livestock that can synthesise GLA.

  18. Histidine-41 of the cytochrome b5 domain of the borage delta6 fatty acid desaturase is essential for enzyme activity.

    PubMed

    Sayanova, O; Shewry, P R; Napier, J A

    1999-10-01

    Unlike most other plant microsomal desaturases, the Delta6-fatty acid desaturase from borage (Borago officinalis) contains an N-terminal extension that shows homology to the small hemoprotein cytochrome (Cyt) b5. To determine if this domain serves as a functional electron donor for the Delta6-fatty acid desaturase, mutagenesis and functional analysis by expression in transgenic Arabidopsis was carried out. Although expression of the wild-type borage Delta6-fatty acid desaturase resulted in the synthesis and accumulation of Delta6-unsaturated fatty acids, this was not observed in plants transformed with N-terminally deleted forms of the desaturase. Site-directed mutagenesis was used to disrupt one of the axial heme-binding residues (histidine-41) of the Cyt b5 domain; expression of this mutant form of the Delta6-desaturase in transgenic plants failed to produce Delta6-unsaturated fatty acids. These data indicate that the Cyt b5 domain of the borage Delta6-fatty acid desaturase is essential for enzymatic activity.

  19. Identification of a Desaturase Involved in Mycolic Acid Biosynthesis in Mycobacterium smegmatis

    PubMed Central

    Singh, Albel; Varela, Cristian; Bhatt, Kiranmai; Veerapen, Natacha; Lee, Oona Y. C.; Wu, Houdini H. T.; Besra, Gurdyal S.; Minnikin, David E.; Fujiwara, Nagatoshi; Teramoto, Kanae; Bhatt, Apoorva

    2016-01-01

    Mycolic acids are unique long chain fatty acids found in the cell walls of mycobacteria including the tubercle bacillus, Mycobacterium tuberculosis. The introduction of double bonds in mycolic acids remains poorly understood, however, genes encoding two potential aerobic desaturases have been proposed to be involved in this process. Here we show that one of these genes, desA1, is essential for growth of the saprophytic Mycobacterium smegmatis. Depletion of desA1 in a M. smegmatis conditional mutant led to reduction of mycolic acid biosynthesis and loss of viability. The DesA1-depleted cells exhibited two other phenotypes: using 14[C]-labelling, we detected the accumulation of minor mycolic acid-related species that migrated faster in a silver TLC plate. Spiral Time of Flight Mass Spectroscopic analysis suggested the presence of species with sizes corresponding to what were likely monoenoic derivatives of α-mycolic acids. Additionally, conditional depletion led to the presence of free fatty acyl species of lengths ~C26-C48 in the lysing cells. Cell viability could be rescued in the conditional mutant by Mycobacterium tuberculosis desA1, highlighting the potential of desA1 as a new drug target in pathogenic mycobacteria. PMID:27741286

  20. Fatty Acid Desaturase Mutants of Yeast: Growth Requirements and Electron Spin Resonance Spin-Label Distribution

    PubMed Central

    Wisnieski, Bernadine J.; Kiyomoto, Richard K.

    1972-01-01

    Two respiratory-sufficient and one respiratory-deficient (nuclear petite) strains of yeast Δ9-desaturase mutants were analyzed to determine which fatty acids would serve as replacements for the naturally occurring fatty acids, 16:1 Δ9cis and 18:1 Δ9cis. The requirement can be satisfied by several fatty acids differing in double-bond position, steric configuration, chain length, and degree of unsaturation. The features common to growth-supporting fatty acids are presented and the effects of varying the carbon source and temperature are considered. In addition, we illustrate several pitfalls encountered in membrane studies which exploit lipid-requiring organisms. Since the membrane fatty acid composition of these mutants can be modified readily, electron spin resonance spectroscopy is used to compare membranes of mutant strains enriched for different fatty acids. The lipid distribution pattern of the most commonly employed electron spin resonance spin-label, 12-nitroxide stearate, was ascertained and compared to that of 18:1 Δ9cis. PMID:4333377

  1. Devolopmental and growth temperature regulation of omega-3 fatty acid desaturase genes in safflower (Carthamus tinctorius L.).

    PubMed

    Guan, L-L; Wu, W; Hu, B; Li, D; Chen, J-W; Hou, K; Wang, L

    2014-08-28

    Three ω-3 fatty acid desaturase genes (CtFAD3, CtFAD7, and CtFAD8) were isolated from safflower (Carthamus tinctorius L.). Transcript analysis showed that the highest transcript levels were detected for CtFAD3 and the low transcript levels were detected for CtFAD7 and CtFAD8 in flowers. This result indicates that CtFAD3 enzyme activity is important for fatty acid desaturation in flowers. The low transcript level of CtFAD3 in developing seeds was consistent with the recorded high level of linoleic acid (18:2) and lack of linolenic acid (18:3) in safflower seed oil. At low temperatures, the induced transcription levels of ω-3 fatty acid desaturase genes in the stems and petioles were consistent with increased polyunsaturated fatty acids (PUFAs). In the roots, ω-3 fatty acid desaturase noticeably increased at low temperatures, whereas PUFA levels decreased. Interestingly, C18:3(Δ9,12,15) alcohol was specifically found in safflower roots, and showed a significant increase, indicating a flux in the acid to alcohol ratio of this compound in safflower roots.

  2. Identification of amino acid residues that determine the substrate specificity of mammalian membrane-bound front-end fatty acid desaturases[S

    PubMed Central

    Watanabe, Kenshi; Ohno, Makoto; Taguchi, Masahiro; Kawamoto, Seiji; Ono, Kazuhisa; Aki, Tsunehiro

    2016-01-01

    Membrane-bound desaturases are physiologically and industrially important enzymes that are involved in the production of diverse fatty acids such as polyunsaturated fatty acids and their derivatives. Here, we identified amino acid residues that determine the substrate specificity of rat Δ6 desaturase (D6d) acting on linoleoyl-CoA by comparing its amino acid sequence with that of Δ5 desaturase (D5d), which converts dihomo-γ-linolenoyl-CoA. The N-terminal cytochrome b5-like domain was excluded as a determinant by domain swapping analysis. Substitution of eight amino acid residues (Ser209, Asn211, Arg216, Ser235, Leu236, Trp244, Gln245, and Val344) of D6d with the corresponding residues of D5d by site-directed mutagenesis switched the substrate specificity from linoleoyl-CoA to dihomo-γ-linolenoyl-CoA. In addition, replacement of Leu323 of D6d with Phe323 on the basis of the amino acid sequence of zebra fish Δ5/6 bifunctional desaturase was found to render D6d bifunctional. Homology modeling of D6d using recent crystal structure data of human stearoyl-CoA (Δ9) desaturase revealed that Arg216, Trp244, Gln245, and Leu323 are located near the substrate-binding pocket. To our knowledge, this is the first report on the structural basis of the substrate specificity of a mammalian front-end fatty acid desaturase, which will aid in efficient production of value-added fatty acids. PMID:26590171

  3. Multiplex PCR assay for detection of recombinant genes encoding fatty acid desaturases fused with lichenase reporter protein in GM plants.

    PubMed

    Berdichevets, Iryna N; Shimshilashvili, Hristina R; Gerasymenko, Iryna M; Sindarovska, Yana R; Sheludko, Yuriy V; Goldenkova-Pavlova, Irina V

    2010-07-01

    Thermostable lichenase encoded by licB gene of Clostridium thermocellum can be used as a reporter protein in plant, bacterial, yeast, and mammalian cells. It has important advantages of high sensitivity and specificity in qualitative and quantitative assays. Deletion variants of LicB (e.g., LicBM3) retain its enzymatic activity and thermostability and can be expressed in translational fusion with target proteins without compromising with their properties. Fusion with the lichenase reporter is especially convenient for the heterologous expression of proteins whose analysis is difficult or compromised by host enzyme activities, as it is in case of fatty acid desaturases occurring in all groups of organisms. Recombinant desaturase-lichenase genes can be used for creating genetically modified (GM) plants with improved chill tolerance. Development of an analytical method for detection of fused desaturase-lichenase transgenes is necessary both for production of GM plants and for their certification. Here, we report a multiplex polymerase chain reaction method for detection of desA and desC desaturase genes of cyanobacteria Synechocystis sp. PCC6803 and Synechococcus vulcanus, respectively, fused to licBM3 reporter in GM plants.

  4. Selection in Europeans on fatty acid desaturases associated with dietary changes.

    PubMed

    Buckley, Matthew T; Racimo, Fernando; Allentoft, Morten E; Jensen, Majken K; Jonsson, Anna; Huang, Hongyan; Hormozdiari, Farhad; Sikora, Martin; Marnetto, Davide; Eskin, Eleazar; Jørgensen, Marit E; Grarup, Niels; Pedersen, Oluf; Hansen, Torben; Kraft, Peter; Willerslev, Eske; Nielsen, Rasmus

    2017-03-16

    FADS genes encode fatty acid desaturases that are important for the conversion of short chain polyunsaturated fatty acids (PUFAs) to long chain fatty acids. Prior studies indicate that the FADS genes have been subjected to strong positive selection in Africa, South Asia, Greenland, and Europe. By comparing FADS sequencing data from present-day and Bronze Age (5-3k years ago) Europeans, we identify possible targets of selection in the European population, which suggest that selection has targeted different alleles in the FADS genes in Europe than it has in South Asia or Greenland. The alleles showing the strongest changes in allele frequency since the Bronze Age show associations with expression changes and multiple lipid-related phenotypes. Furthermore, the selected alleles are associated with a decrease in linoleic acid and an increase in arachidonic and eicosapentaenoic acids among Europeans; this is an opposite effect of that observed for selected alleles in Inuit from Greenland. We show that multiple SNPs in the region affect expression levels and PUFA synthesis. Additionally, we find evidence for a gene-environment interaction influencing low-density lipoprotein (LDL) levels between alleles affecting PUFA synthesis and PUFA dietary intake: carriers of the derived allele display lower LDL cholesterol levels with a higher intake of PUFAs. We hypothesize that the selective patterns observed in Europeans were driven by a change in dietary composition of fatty acids following the transition to agriculture, resulting in a lower intake of arachidonic acid and eicosapentaenoic acid, but a higher intake of linoleic acid and α-linolenic acid.

  5. Desaturase and elongase limiting endogenous long chain polyunsaturated fatty acid biosynthesis

    PubMed Central

    Zhang, Ji Yao; Kothapalli, Kumar S.D.; Brenna, J. Thomas

    2016-01-01

    Purpose of Review Endogenous synthesis of the long chain polyunsaturated fatty acids (LCPUFA) is mediated by the fatty acid desaturase (FADS) gene cluster (11q12-13.1) and elongation of very long chain fatty acids 2 (ELOVL2) (6p24.2) and ELOVL5 (6p12.1). Though older biochemical work identified the product of one gene, FADS2, rate limiting for LCPUFA synthesis, recent studies suggest that polymorphisms in any of these genes can limit accumulation of product LCPUFA. Recent findings Genome-wide association study (GWAS) of Greenland Inuit show strong adaptation signals within FADS gene cluster, attributed to high omega-3 fatty acid intake, while GWAS found ELOVL2 associated with sleep duration, age and DNA methylation. ELOVL5 coding mutations cause spinocerebellar ataxia 38, and epigenetic marks were associated with depression and suicide risk. Two sterol response element binding sites were found on ELOVL5, a SREBP-1c target gene. Minor allele carriers of a 3 single nucleotide polymorphism (SNP) haplotype in ELOVL2 have decreased 22:6n-3 levels. Unequivocal molecular evidence shows mammalian FADS2 catalyzes direct Δ4-desaturation to yield 22:6n-3 and 22:5n-6. A SNP near FADS1 influences the levels of 5-lipoxygenase products and epigenetic alteration. Summary Genetic polymorphisms within FADS and ELOVL can limit LCPUFA product accumulation at any step of the biosynthetic pathway. PMID:26828581

  6. Genome-wide identification and expression profiling of the fatty acid desaturase gene family in the silkworm, Bombyx mori.

    PubMed

    Chen, Q M; Cheng, D J; Liu, S P; Ma, Z G; Tan, X; Zhao, P

    2014-05-13

    Fatty acid desaturases exist in all living organisms and play important roles in many different biologic processes, such as fatty acid metabolism, lipid biosynthetic processes, and pheromone biosynthetic processes. Using the available silkworm genome sequence, we identified 14 candidate fatty acid desaturase genes. Eleven genes contain 3 conserved histidine cluster motifs and 4 transmembrane domains, but their N-terminal residues exhibit obvious diversity. Phylogenetic analysis revealed that there are 6 groups; Bmdesat1 and Bmdesat5-8 were clustered into group 2, which is involved in Δ11 desaturation activity, and Bmdesat3-4 were grouped in group 1, which is involved in Δ9 desaturation activity. Twelve of the 14 genes have expressed sequence tag evidence. Microarray data and reverse transcription polymerase chain reaction analysis demonstrated that Bmdesat3-4 and Bmdesat10 were expressed from the larval to moth stages and in multiple tissues on day 3 of 5th instar larvae. Bmdesat9, Bmdesat11, and Bmdesat14 were expressed during the pupal and late-embryonic stage, suggesting that they may take part in fatty acid metabolism to provide energy. These results provide some insights into the functions of individual fatty acid desaturases in silkworm.

  7. Genomic structural analysis of porcine fatty acid desaturase cluster on chromosome 2.

    PubMed

    Taniguchi, Masaaki; Arakawa, Aisaku; Motoyama, Michiyo; Nakajima, Ikuyo; Nii, Masahiro; Mikawa, Satoshi

    2015-04-01

    Fatty acid composition is an economically important trait in meat-producing livestock. To gain insight into the molecular genetics of fatty acid desaturase (FADS) genes in pigs, we investigated the genomic structure of the porcine FADS gene family on chromosome 2. We also examined the tissue distribution of FADS gene expression. The genomic structure of FADS family in mammals consists of three isoforms FADS1, FADS2 and FADS3. However, porcine FADS cluster in the latest pig genome assembly (Sscrofa 10.2) containing some gaps is distinct from that in other mammals. We therefore sought to determine the genomic structure, including the FADS cluster in a 200-kbp range by sequencing gap regions. The structure we obtained was similar to that in other mammals. We then investigated the porcine FADS1 transcription start site and identified a novel isoform named FADS1b. Phylogenetic analysis revealed that the three members of the FADS cluster were orthologous among mammals, whereas the various FADS1 isoforms identified in pigs, mice and cattle might be attributable to species-specific transcriptional regulation with alternative promoters. Porcine FADS1b and FADS3 isoforms were predominantly expressed in the inner layer of the subcutaneous adipose tissue. Additional analyses will reveal the effects of these functionally unknown isoforms on fatty acid composition in pig fat tissues.

  8. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, E.B.; Shanklin, J.; Lindgvist, Y.; Schneider, G.

    1998-01-06

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity. 1 fig.

  9. Dietary and ontogenic regulation of fatty acid desaturase and elongase expression in broiler chickens.

    PubMed

    Jing, M; Gakhar, N; Gibson, R A; House, J D

    2013-08-01

    Effects of diet and ontogeny on the expression of fatty acid desaturases and elongases were examined in broiler chickens. In Study 1, 120 day-old male chicks received one of six diets with LA:ALA ranging from 46:4 to 16:34, for 33 days. Total n-6 PUFA decreased, and n-3 PUFA increased in response to a decrease in the dietary LA:ALA. FADS1, FADS2, ELOVL2 and ELOVL5 mRNAs were highest (P<0.05) in birds fed lower LA:ALA diets. In Study 2, 60 day-old male chicks were fed a basal diet, and liver samples were collected on day of hatch, and on days 2, 7, 14, 21 and 35 post-hatch. Total n-6 and n-3 PUFA increased (P<0.01) from days 7 to days 21. FADS1, FADS2 and ELOVL2 mRNAs generally increased (P<0.01) with age. These findings provide evidence for the dietary and developmental regulation of PUFA metabolism in broiler chickens.

  10. Plasma sulfur amino acids and stearoyl-CoA desaturase activity in two Caucasian populations.

    PubMed

    Vinknes, K J; Dekker, J M; Drevon, C A; Refsum, H; Nurk, E; Nijpels, G; Stehouwer, C D A; Teerlink, T; Tell, G S; Nygård, O; Vollset, S E; Ueland, P M; Elshorbagy, A K

    2013-10-01

    In rats, dietary restriction of the cysteine precursor methionine suppresses hepatic stearoyl-CoA desaturase (SCD)-1 expression and activity, whereas cysteine supplementation reverses these effects. In 2 independent cohorts: Hordaland Health Study (HUSK; N=2021, aged 71-74y), Norway, and Hoorn study (N=686, aged 50-87y), Netherlands, we examined the cross-sectional associations of plasma sulfur-containing compounds (SCC; methionine, S-adenosylmethionine, S-adenosylhomocysteine, homocysteine, cystathionine, total cysteine (tCys), glutathione and cysteinylglycine) with SCD-16 index (16:1n-7/16:0), estimated from fatty acid profiles of total plasma or serum lipids. Only tCys was consistently associated with SCD-16 index after adjustments for sex and age (HUSK: partial r=0.14; Hoorn: partial r=0.11, P<0.001 for both), and after further adjustments for other SCC, body fat, diet, exercise and plasma lipids (HUSK: partial r=0.07, P=0.004; Hoorn: partial r=0.12, P=0.013). Together with animal data showing an effect of dietary cysteine on SCD1, our results suggest a role for cysteine in SCD1 regulation in humans.

  11. Diversity of Δ12 Fatty Acid Desaturases in Santalaceae and Their Role in Production of Seed Oil Acetylenic Fatty Acids*

    PubMed Central

    Okada, Shoko; Zhou, Xue-Rong; Damcevski, Katherine; Gibb, Nerida; Wood, Craig; Hamberg, Mats; Haritos, Victoria S.

    2013-01-01

    Plants in the Santalaceae family, including the native cherry Exocarpos cupressiformis and sweet quandong Santalum acuminatum, accumulate ximenynic acid (trans-11-octadecen-9-ynoic acid) in their seed oil and conjugated polyacetylenic fatty acids in root tissue. Twelve full-length genes coding for microsomal Δ12 fatty acid desaturases (FADs) from the two Santalaceae species were identified by degenerate PCR. Phylogenetic analysis of the predicted amino acid sequences placed five Santalaceae FADs with Δ12 FADs, which include Arabidopsis thaliana FAD2. When expressed in yeast, the major activity of these genes was Δ12 desaturation of oleic acid, but unusual activities were also observed: i.e. Δ15 desaturation of linoleic acid as well as trans-Δ12 and trans-Δ11 desaturations of stearolic acid (9-octadecynoic acid). The trans-12-octadecen-9-ynoic acid product was also detected in quandong seed oil. The two other FAD groups (FADX and FADY) were present in both species; in a phylogenetic tree of microsomal FAD enzymes, FADX and FADY formed a unique clade, suggesting that are highly divergent. The FADX group enzymes had no detectable Δ12 FAD activity but instead catalyzed cis-Δ13 desaturation of stearolic acid when expressed in yeast. No products were detected for the FADY group when expressed recombinantly. Quantitative PCR analysis showed that the FADY genes were expressed in leaf rather than developing seed of the native cherry. FADs with promiscuous and unique activities have been identified in Santalaceae and explain the origin of some of the unusual lipids found in this plant family. PMID:24062307

  12. Reducing saturated fatty acids in Arabidopsis seeds by expression of a Caenorhabditis elegans 16:0-specific desaturase.

    PubMed

    Fahy, Deirdre; Scheer, Barbara; Wallis, James G; Browse, John

    2013-05-01

    Plant oilseeds are a major source of nutritional oils. Their fatty acid composition, especially the proportion of saturated and unsaturated fatty acids, has important effects on human health. Because intake of saturated fats is correlated with the incidence of cardiovascular disease and diabetes, a goal of metabolic engineering is to develop oils low in saturated fatty acids. Palmitic acid (16:0) is the most abundant saturated fatty acid in the seeds of many oilseed crops and in Arabidopsis thaliana. We expressed FAT-5, a membrane-bound desaturase cloned from Caenorhabditis elegans, in Arabidopsis using a strong seed-specific promoter. The FAT-5 enzyme is highly specific to 16:0 as substrate, converting it to 16:1∆9; expression of fat-5 reduced the 16:0 content of the seed by two-thirds. Decreased 16:0 and elevated 16:1 levels were evident both in the storage and membrane lipids of seeds. Regiochemical analysis of phosphatidylcholine showed that 16:1 was distributed at both positions on the glycerolipid backbone, unlike 16:0, which is predominately found at the sn-1 position. Seeds from a plant line homozygous for FAT-5 expression were comparable to wild type with respect to seed set and germination, while oil content and weight were somewhat reduced. These experiments demonstrate that targeted heterologous expression of a desaturase in oilseeds can reduce the level of saturated fatty acids in the oil, significantly improving its nutritional value.

  13. Characterization of the Fatty Acid Desaturase Genes in Cucumber: Structure, Phylogeny, and Expression Patterns

    PubMed Central

    Dong, Chun-Juan; Cao, Ning; Zhang, Zhi-Gang; Shang, Qing-Mao

    2016-01-01

    Fatty acid desaturases (FADs) introduce double bonds into the hydrocarbon chains of fatty acids to produce unsaturated fatty acids, and therefore play a critical role in plant development and acclimation to environmental stresses. In this study, 23 full-length FAD genes in cucumber (Cucumis sativus L.) were identified through database searches, including three CsFAB2 genes, two CsFAD2 genes, fourteen CsFAD5 genes, and one gene each for CsFAD3, CsFAD4, CsFAD6 and CsFAD7. These cucumber FAD genes were distributed on all seven chromosomes and two additional scaffolds. Based on a phylogenetic analysis, the cucumber FAD proteins were clustered into five subfamilies with their counterparts from other plants. Gene structures and protein sequences were considerably conserved in each subfamily. All three CsFAB2 proteins shared conserved structure with the known plant soluble FAD proteins. The other cucumber FADs belonged to the membrane-bound FADs and contained three highly conserved histidine boxes. Additionally, the putative endoplasmic reticulum retention signal was found at the C-termini of the CsFAD2 and CsFAD3 proteins, while the N-termini of CsFAD4, CsFAD5, CsFAD6, CsFAD7 and three CsFAB2s contained a predicted chloroplast signal peptide, which was consistent with their associated metabolic pathways. Furthermore, a gene expression analysis showed that CsFAD2 and CsFAD3 were universally expressed in all tested tissues, whereas the other cucumber FAD genes were preferentially expressed in the cotyledons or leaves. The tissue-specific expression patterns of cucumber FAD genes were correlated well with the differences in the fatty acid compositions ofroots and leaves. Finally, the cucumber FAD genes showed a cold-induced and heat-repressed expression pattern, although with distinct regulatory time courses among the different CsFAD members, which indicates the potential roles of the FADs in temperature stress resistance in cucumber. PMID:26938877

  14. Characterization of three novel desaturases involved in the delta-6 desaturation pathways for polyunsaturated fatty acid biosynthesis from Phytophthora infestans.

    PubMed

    Sun, Quanxi; Liu, Jiang; Zhang, Qin; Qing, Xiaohe; Dobson, Gary; Li, Xinzheng; Qi, Baoxiu

    2013-09-01

    Phytophthora infestans is the causative agent of potato blight that resulted in the great famine in Ireland in the nineteenth century. This microbe can release large amounts of the C20 very long-chain polyunsaturated fatty acids arachidonic acid (ARA; 20:4Δ(5, 8, 11, 14)) and eicosapentaenoic acid (EPA; 20:5Δ(5, 8, 11, 14, 17)) upon invasion that is known to elicit a hypersensitive response to their host plant. In order to identify enzymes responsible for the biosynthesis of these fatty acids, we blasted the recently fully sequenced P. infestans genome and identified three novel putatively encoding desaturase sequences. These were subsequently functionally characterized by expression in Saccharomyces cerevisiae and confirmed that they encode desaturases with Δ12, Δ6 and Δ5 activity, designated here as PinDes12, PinDes6 and PinDes5, respectively. This, together with the combined fatty acid profiles and a previously identified Δ6 elongase activity, implies that the ARA and EPA are biosynthesized predominantly via the Δ6 desaturation pathways in P. infestans. Elucidation of ARA and EPA biosynthetic mechanism may provide new routes to combating this potato blight microbe directly or by means of conferring resistance to important crops.

  15. Modification of fatty acid composition in tomato (Lycopersicon esculentum) by expression of a borage delta6-desaturase.

    PubMed

    Cook, David; Grierson, Don; Jones, Craigh; Wallace, Andrew; West, Gill; Tucker, Greg

    2002-06-01

    The improvement of nutritional quality is one potential application for the genetic modification of plants. One possible target for such manipulation is the modification of fatty acid metabolism. In this work, expression of a borage delta6-desaturase cDNA in tomato (Lycopersicon esculentum L.) has been shown to produce gamma-linolenic acid (GLA; 18:83 delta6,9,12) and octadecatetraenoic acid (OTA; 18:4 delta6,9,12,15) in transgenic leaf and fruit tissue. This genetic modification has also, unexpectedly, resulted in a reduction in the percentage of linoleic acid (LA 18:2 delta9,12) and a concomitant increase in the percentage of alpha-linolenic acid (ALA; 18:3 delta9,12,15) in fruit tissue. These changes in fatty acid composition are thought to be beneficial for human health.

  16. Biosynthesis of Polyunsaturated Fatty Acids in Sea Urchins: Molecular and Functional Characterisation of Three Fatty Acyl Desaturases from Paracentrotus lividus (Lamark 1816).

    PubMed

    Kabeya, Naoki; Sanz-Jorquera, Alicia; Carboni, Stefano; Davie, Andrew; Oboh, Angela; Monroig, Oscar

    2017-01-01

    Sea urchins are broadly recognised as a delicacy and their quality as food for humans is highly influenced by their diet. Lipids in general and the long-chain polyunsaturated fatty acids (LC-PUFA) in particular, are essential nutrients that determine not only the nutritional value of sea urchins but also guarantee normal growth and reproduction in captivity. The contribution of endogenous production (biosynthesis) of LC-PUFA in sea urchins remained unknown. Using Paracentrotus lividus as our model species, we aimed to characterise both molecularly and functionally the repertoire of fatty acyl desaturases (Fads), key enzymes in the biosynthesis of LC-PUFA, in sea urchins. Three Fads, namely FadsA, FadsC1 and FadsC2, were characterised. The phylogenetic analyses suggested that the repertoire of Fads within the Echinodermata phylum varies among classes. On one hand, orthologues of the P. lividus FadsA were found in other echinoderm classes including starfishes, brittle stars and sea cucumbers, thus suggesting that this desaturase is virtually present in all echinoderms. Contrarily, the FadsC appears to be sea urchin-specific desaturase. Finally, a further desaturase termed as FadsB exists in starfishes, brittle stars and sea cucumbers, but appears to be missing in sea urchins. The functional characterisation of the P. lividus Fads confirmed that the FadsA was a Δ5 desaturase with activity towards saturated and polyunsaturated fatty acids (FA). Moreover, our experiments confirmed that FadsA plays a role in the biosynthesis of non-methylene interrupted FA, a group of compounds typically found in marine invertebrates. On the other hand, both FadsC desaturases from P. lividus showed Δ8 activity. The present results demonstrate that P. lividus possesses desaturases that account for all the desaturation reactions required to biosynthesis the physiological essential eicosapentaenoic and arachidonic acids through the so-called "Δ8 pathway".

  17. Biosynthesis of Polyunsaturated Fatty Acids in Sea Urchins: Molecular and Functional Characterisation of Three Fatty Acyl Desaturases from Paracentrotus lividus (Lamark 1816)

    PubMed Central

    Carboni, Stefano; Davie, Andrew; Oboh, Angela

    2017-01-01

    Sea urchins are broadly recognised as a delicacy and their quality as food for humans is highly influenced by their diet. Lipids in general and the long-chain polyunsaturated fatty acids (LC-PUFA) in particular, are essential nutrients that determine not only the nutritional value of sea urchins but also guarantee normal growth and reproduction in captivity. The contribution of endogenous production (biosynthesis) of LC-PUFA in sea urchins remained unknown. Using Paracentrotus lividus as our model species, we aimed to characterise both molecularly and functionally the repertoire of fatty acyl desaturases (Fads), key enzymes in the biosynthesis of LC-PUFA, in sea urchins. Three Fads, namely FadsA, FadsC1 and FadsC2, were characterised. The phylogenetic analyses suggested that the repertoire of Fads within the Echinodermata phylum varies among classes. On one hand, orthologues of the P. lividus FadsA were found in other echinoderm classes including starfishes, brittle stars and sea cucumbers, thus suggesting that this desaturase is virtually present in all echinoderms. Contrarily, the FadsC appears to be sea urchin-specific desaturase. Finally, a further desaturase termed as FadsB exists in starfishes, brittle stars and sea cucumbers, but appears to be missing in sea urchins. The functional characterisation of the P. lividus Fads confirmed that the FadsA was a Δ5 desaturase with activity towards saturated and polyunsaturated fatty acids (FA). Moreover, our experiments confirmed that FadsA plays a role in the biosynthesis of non-methylene interrupted FA, a group of compounds typically found in marine invertebrates. On the other hand, both FadsC desaturases from P. lividus showed Δ8 activity. The present results demonstrate that P. lividus possesses desaturases that account for all the desaturation reactions required to biosynthesis the physiological essential eicosapentaenoic and arachidonic acids through the so-called “Δ8 pathway”. PMID:28052125

  18. Identification and expression of a stearoyl-ACP desaturase gene responsible for oleic acid accumulation in Xanthoceras sorbifolia seeds.

    PubMed

    Zhao, Na; Zhang, Yuan; Li, Qiuqi; Li, Rufang; Xia, Xinli; Qin, Xiaowei; Guo, Huihong

    2015-02-01

    Xanthoceras sorbifolia Bunge is an oilseed tree that grows well on barren lands in dry climate. Its seeds contain a large amount of oil rich in oleic acid (18:1(Δ9)) and linoleic acid (18:2(Δ9, 12)). However, the molecular regulation of oil biosynthesis in X. sorbifolia seeds is poorly understood. Stearoyl-ACP desaturase (SAD, EC 1.14.99.6) is a plastid-localized soluble desaturase that catalyzes the conversion of stearic acid (18:0) to oleic acid, which plays a key role in determining the ratio of saturated to unsaturated fatty acids. In this study, a full-length cDNA of XsSAD was isolated from developing X. sorbifolia embryos. The XsSAD open reading frame had 1194-bp, encoding a polypeptide of 397 amino acids. XsSAD expression in Escherichia coli cells resulted in increased 18:1(Δ9) level, confirming the biological activity of the enzyme encoded by XsSAD. XsSAD expression in Arabidopsis ssi2 mutants partially restored the morphological phenotype and effectively increased the 18:1(Δ9) level. The levels of other unsaturated fatty acids synthesized with 18:1(Δ9) as the substrate also increased to some degree. XsSAD in X. sorbifolia had a much higher expression in embryos than in leaves and petals. XsSAD expression also correlated well with the oleic acid, unsaturated fatty acid, and total fatty acid levels in developing embryos. These data suggested that XsSAD determined the synthesis of oleic acid and contributed to the accumulation of unsaturated fatty acid and total oil in X. sorbifolia seeds. A preliminary tobacco rattle virus-based virus-induced gene silencing system established in X. sorbifolia can also be helpful for further analyzing the functions of XsSAD and other oil synthesis-related genes in woody plants.

  19. Genome-wide analysis of the omega-3 fatty acid desaturase gene family in Gossypium

    DOE PAGES

    Yurchenko, Olga P.; Park, Sunjung; Ilut, Daniel C.; ...

    2014-11-18

    The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid tropical and subtropical regions, and thus perform well in these geographical areas, cotton seedlings are sensitive to cold temperature, which can significantly reduce crop yields. One of the common biochemical responses of plants to cold temperatures is an increase in omega-3 fatty acids, which protects cellular function by maintaining membrane integrity. The purpose of our study was to identify and characterizemore » the omega-3 fatty acid desaturase (FAD) gene family in G. hirsutum, with an emphasis on identifying omega-3 FADs involved in cold temperature adaptation. Results: Eleven omega-3 FAD genes were identified in G. hirsutum, and characterization of the gene family in extant A and D diploid species (G. herbaceum and G. raimondii, respectively) allowed for unambiguous genome assignment of all homoeologs in tetraploid G. hirsutum. The omega-3 FAD family of cotton includes five distinct genes, two of which encode endoplasmic reticulum-type enzymes (FAD3-1 and FAD3-2) and three that encode chloroplast-type enzymes (FAD7/8-1, FAD7/8-2, and FAD7/8-3). The FAD3-2 gene was duplicated in the A genome progenitor species after the evolutionary split from the D progenitor, but before the interspecific hybridization event that gave rise to modern tetraploid cotton. RNA-seq analysis revealed conserved, gene-specific expression patterns in various organs and cell types and semi-quantitative RT-PCR further revealed that FAD7/8-1 was specifically induced during cold temperature treatment of G. hirsutum seedlings. Conclusions: The omega-3 FAD gene family in cotton was characterized at the genome-wide level in three species, showing relatively ancient establishment of the gene family prior

  20. Arabidopsis fatty acid desaturase FAD2 is required for salt tolerance during seed germination and early seedling growth.

    PubMed

    Zhang, Jiantao; Liu, Hua; Sun, Jian; Li, Bei; Zhu, Qiang; Chen, Shaoliang; Zhang, Hongxia

    2012-01-01

    Fatty acid desaturases play important role in plant responses to abiotic stresses. However, their exact function in plant resistance to salt stress is unknown. In this work, we provide the evidence that FAD2, an endoplasmic reticulum localized ω-6 desaturase, is required for salt tolerance in Arabidopsis. Using vacuolar and plasma membrane vesicles prepared from the leaves of wild-type (Col-0) and the loss-of-function Arabidopsis mutant, fad2, which lacks the functional FAD2, we examined the fatty acid composition and Na+-dependent H+ movements of the isolated vesicles. We observed that, when compared to Col-0, the level of vacuolar and plasma membrane polyunsaturation was lower, and the Na+/H+ exchange activity was reduced in vacuolar and plasma membrane vesicles isolated from fad2 mutant. Consistent with the reduced Na+/H+ exchange activity, fad2 accumulated more Na+ in the cytoplasm of root cells, and was more sensitive to salt stress during seed germination and early seedling growth, as indicated by CoroNa-Green staining, net Na+ efflux and salt tolerance analyses. Our results suggest that FAD2 mediated high-level vacuolar and plasma membrane fatty acid desaturation is essential for the proper function of membrane attached Na+/H+ exchangers, and thereby to maintain a low cytosolic Na+ concentration for salt tolerance during seed germination and early seedling growth in Arabidopsis.

  1. The N termini of Brassica and tung omega-3 fatty acid desaturases mediate proteasome-dependent protein degradation in plant cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The regulation of fatty acid desaturase activity in plants is important for determining the polyunsaturated fatty acid content of cellular membranes, which is often rapidly adjusted in plant cells in response to temperature change. Recent studies have demonstrated that the endoplasmic reticulum (ER)...

  2. TEMPERATURE-SENSITIVE, POST-TRANSLATIONAL REGULATION OF PLANT OMEGA-3 FATTY ACID DESATURASES IS MEDIATED BY THE ER-ASSOCIATED DEGRADATION PATHWAY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In plants, the endoplasmic reticulum (ER)-localized omega-3 fatty acid desaturases (Fad3s) increase the production of polyunsaturated fatty acids at cooler temperatures, but the FAD3 genes themselves are typically not upregulated during this adaptive response. Here, we expressed two closely related ...

  3. Mutations in a delta9-Stearoyl-ACP-Desaturase Gene Are Associated with Enhanced Stearic Acid Levels in Soybean Seeds

    SciTech Connect

    Zhang, P.; Shanklin, J.; Burton, J. W.; Upchurch, R. G.; Whittle, E.; Dewey, R. E.

    2008-11-01

    Stearic acid (18:0) is typically a minor component of soybean [Glycine max (L.) Merr.] oil, accounting for only 2 to 4% of the total fatty acid content. Increasing stearic acid levels of soybean oil would lead to enhanced oxidative stability, potentially reducing the need for hydrogenation, a process leading to the formation of undesirable trans fatty acids. Although mutagenesis strategies have been successful in developing soybean germplasm with elevated 18:0 levels in the seed oil, the specific gene mutations responsible for this phenotype were not known. We report a newly identified soybean gene, designated SACPD-C, that encodes a unique isoform of {Delta}{sup 9}-stearoyl-ACP-desaturase, the enzyme responsible for converting stearic acid to oleic acid (18:1). High levels of SACPD-C transcript were only detected in developing seed tissue, suggesting that the encoded desaturase functions to enhance oleic acid biosynthetic capacity as the immature seed is actively engaged in triacylglycerol production and storage. The participation of SACPD-C in storage triacylglycerol synthesis is further supported by the observation of mutations in this gene in two independent sources of elevated 18:0 soybean germplasm, A6 (30% 18:0) and FAM94-41 (9% 18:0). A molecular marker diagnostic for the FAM94-41 SACPD-C gene mutation strictly associates with the elevated 18:0 phenotype in a segregating population, and could thus serve as a useful tool in the development of cultivars with oils possessing enhanced oxidative stability.

  4. Association of serum fatty acid and estimated desaturase activity with hypertension in middle-aged and elderly Chinese population

    PubMed Central

    Yang, Bo; Ding, Fang; Wang, Feng-Lei; Yan, Jing; Ye, Xiong-Wei; Yu, Wei; Li, Duo

    2016-01-01

    We aimed to investigate the cross-sectional associations of serum fatty acid (FA) and related Δ-desaturase with hypertension among 2,447 community-dwellers aged 35–79 years living in Zhejiang Province, China. Individual FA was determined in serum, Δ5-desaturase (D5D) and Δ6-desaturase (D6D) activities were indirectly estimated by FA product/precursor ratios. Participants in the highest quartile of D5D component scores (20:4n–6, 20:5n–3, 22:6n–3 and D5D) have significantly lower odds of hypertension compared with individuals in the lowest (multivariate-adjusted odds ratio (OR) = 0.68, 95% CI: 0.46–0.98). When further stratified by gender, high D5D component scores were significantly associated with lower odds of hypertension in women (OR = 0.53, 95% CI: 0.35–0.80), but not in men (OR = 0.78, 95% CI: 0.52-1.18). Multivariate-adjusted prevalent OR for an interquartile increment of individual FA and estimated desaturase was 1.27 (95% CI: 1.08–1.50) for 16:0, 1.15 (95% CI: 1.01–1.30) for 16:1n–7, 0.89 (95% CI: 0.80–0.99) for 22:6n–3, 1.32 (95% CI: 1.01–1.72) for D6D (18:3n–6/18:2n–6), and 0.74 (95% CI: 0.56, 0.98) for D5D (20:4n–6/20:3n–6). Present findings suggested that high serum 22:6n–3 and D5D as well as low 16:0, 16:1n–7 and D6D were associated with a low prevalence of hypertension in this Chinese population. PMID:27006169

  5. Adipose tissue stearoyl-CoA desaturase 1 index is increased and linoleic acid is decreased in obesity-prone rats fed a high-fat diet

    PubMed Central

    2013-01-01

    Background Fatty acid (FA) composition and desaturase indices are associated with obesity and related metabolic conditions. However, it is unclear to what extent desaturase activity in different lipid fractions contribute to obesity susceptibility. Our aim was to test whether desaturase activity and FA composition are linked to an obese phenotype in rats that are either obesity prone (OP) or resistant (OR) on a high-fat diet (HFD). Methods Two groups of Sprague–Dawley rats were given ad libitum (AL-HFD) or calorically restricted (HFD-paired; pair fed to calories consumed by chow-fed rats) access to a HFD. The AL-HFD group was categorized into OP and OR sub-groups based on weight gain over 5 weeks. Five different lipid fractions were examined in OP and OR rats with regard to proportions of essential and very long-chain polyunsaturated FAs: linoleic acid (LA), alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and the stearoyl-CoA desaturase 1 (SCD-1) product 16:1n-7. FA ratios were used to estimate activities of the delta-5-desaturase (20:4n-6/20:3n-6), delta-6-desaturase (18:3n-6/18:2n-6), stearoyl-CoA desaturase 1 (SCD-1; 16:1n-7/16:0, SCD-16 and 18:1n-9/18:0, SCD-18), de novo lipogenesis (16:0/18:2n-6) and FA elongation (18:0/16:0). Fasting insulin, glucose, adiponectin and leptin concentrations were measured in plasma. Results After AL-HFD access, OP rats had a significantly higher SCD-16 index and 16:1n-7 proportion, but a significantly lower LA proportion, in subcutaneous adipose tissue (SAT) triacylglycerols, as well as significantly higher insulin and leptin concentrations, compared with OR rats. No differences were found between the two phenotypes in liver (phospholipids; triacylglycerols) or plasma (cholesterol esters; phospholipids) lipid fractions or for plasma glucose or adiponectin concentrations. For the desaturase indices of the HFD-paired rats, the only significant differences compared with the OP or OR rats were higher SCD-16 and

  6. Role of plasma membrane lipid composition on cellular homeostasis: learning from cell line models expressing fatty acid desaturases

    PubMed Central

    Jaureguiberry, María S.; Tricerri, M. Alejandra; Sanchez, Susana A.; Finarelli, Gabriela S.; Montanaro, Mauro A.; Prieto, Eduardo D.; Rimoldi, Omar J.

    2014-01-01

    Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell metabolism and viability depend on lipid composition and organization. The aim of the present work is to develop a cell model to study the endogenous polyunsaturated fatty acids (PUFAs) effect on PM properties and analyze its influence on cholesterol (Chol) homeostasis. We have previously shown that by using a cell line over-expressing stearoyl-CoA-desaturase, membrane composition and organization coordinate cellular pathways involved in Chol efflux and cell viability by different mechanisms. Now, we expanded our studies to a cell model over-expressing both Δ5 and Δ6 desaturases, which resulted in a permanently higher PUFA content in PM. Furthermore, this cell line showed increased PM fluidity, Chol storage, and mitochondrial activity. In addition, human apolipoprotein A-I-mediated Chol removal was less efficient in these cells than in the corresponding control. Taken together, our results suggested that the cell functionality is preserved by regulating PM organization and Chol exportation and homeostasis. PMID:24473084

  7. Role of plasma membrane lipid composition on cellular homeostasis: learning from cell line models expressing fatty acid desaturases.

    PubMed

    Jaureguiberry, María S; Tricerri, M Alejandra; Sanchez, Susana A; Finarelli, Gabriela S; Montanaro, Mauro A; Prieto, Eduardo D; Rimoldi, Omar J

    2014-04-01

    Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell metabolism and viability depend on lipid composition and organization. The aim of the present work is to develop a cell model to study the endogenous polyunsaturated fatty acids (PUFAs) effect on PM properties and analyze its influence on cholesterol (Chol) homeostasis. We have previously shown that by using a cell line over-expressing stearoyl-CoA-desaturase, membrane composition and organization coordinate cellular pathways involved in Chol efflux and cell viability by different mechanisms. Now, we expanded our studies to a cell model over-expressing both Δ5 and Δ6 desaturases, which resulted in a permanently higher PUFA content in PM. Furthermore, this cell line showed increased PM fluidity, Chol storage, and mitochondrial activity. In addition, human apolipoprotein A-I-mediated Chol removal was less efficient in these cells than in the corresponding control. Taken together, our results suggested that the cell functionality is preserved by regulating PM organization and Chol exportation and homeostasis.

  8. Properties of two multifunctional plant fatty acid acetylenase/desaturase enzymes.

    PubMed

    Carlsson, Anders S; Thomaeus, Stefan; Hamberg, Mats; Stymne, Sten

    2004-07-01

    The properties of the Delta6 desaturase/acetylenase from the moss Ceratodon purpureus and the Delta12 acetylenase from the dicot Crepis alpina were studied by expressing the encoding genes in Arabidopsis thaliana and Saccharomyces cerevisiae. The acetylenase from C. alpinaDelta12 desaturated both oleate and linoleate with about equal efficiency. The desaturation of oleate gave rise to 9(Z),12(E)- and 9(Z),12(Z)-octadecadienoates in a ratio of approximately 3 : 1. Experiments using stereospecifically deuterated oleates showed that the pro-R hydrogen atoms were removed from C-12 and C-13 in the introduction of the 12(Z) double bond, whereas the pro-R and pro-S hydrogen atoms were removed from these carbons during the formation of the 12(E) double bond. The results suggested that the Delta12 acetylenase could accommodate oleate having either a cisoid or transoid conformation of the C(12)-C(13) single bond, and that these conformers served as precursors of the 12(Z) and 12(E) double bonds, respectively. However, only the 9(Z),12(Z)-octadecadienoate isomer could be further desaturated to 9(Z)-octadecen-12-ynoate (crepenynate) by the enzyme. The evolutionarily closely related Delta12 epoxygenase from Crepis palaestina had only weak desaturase activity but could also produce 9(Z),12(E)-octadecadienoate from oleate. The Delta6 acetylenase/desaturase from C. purpureus, on the other hand, produced only the 6(Z) isomers using C16 and C18 acyl groups possessing a Delta9 double bond as substrates. The Delta6 double bond was efficiently further converted to an acetylenic bond by a second round of desaturation but only if the acyl substrate had a Delta12 double bond and that this was in the Z configuration.

  9. Targeted mutation of Δ12 and Δ15 desaturase genes in hemp produce major alterations in seed fatty acid composition including a high oleic hemp oil.

    PubMed

    Bielecka, Monika; Kaminski, Filip; Adams, Ian; Poulson, Helen; Sloan, Raymond; Li, Yi; Larson, Tony R; Winzer, Thilo; Graham, Ian A

    2014-06-01

    We used expressed sequence tag library and whole genome sequence mining to identify a suite of putative desaturase genes representing the four main activities required for production of polyunsaturated fatty acids in hemp seed oil. Phylogenetic-based classification and developing seed transcriptome analysis informed selection for further analysis of one of seven Δ12 desaturases and one of three Δ15 desaturases that we designate CSFAD2A and CSFAD3A, respectively. Heterologous expression of corresponding cDNAs in Saccharomyces cerevisiae showed CSFAD2A to have Δx+3 activity, while CSFAD3A activity was exclusively at the Δ15 position. TILLING of an ethyl methane sulphonate mutagenized population identified multiple alleles including non-sense mutations in both genes and fatty acid composition of seed oil confirmed these to be the major Δ12 and Δ15 desaturases in developing hemp seed. Following four backcrosses and sibling crosses to achieve homozygosity, csfad2a-1 was grown in the field and found to produce a 70 molar per cent high oleic acid (18:1(Δ9) ) oil at yields similar to wild type. Cold-pressed high oleic oil produced fewer volatiles and had a sevenfold increase in shelf life compared to wild type. Two low abundance octadecadienoic acids, 18:2(Δ6,9) and 18:2(Δ9,15), were identified in the high oleic oil, and their presence suggests remaining endogenous desaturase activities utilize the increased levels of oleic acid as substrate. Consistent with this, CSFAD3A produces 18:2(Δ9,15) from endogenous 18:1(Δ9) when expressed in S. cerevisiae. This work lays the foundation for the development of additional novel oil varieties in this multipurpose low input crop.

  10. Mutation of Host Δ9 Fatty Acid Desaturase Inhibits Brome Mosaic Virus RNA Replication between Template Recognition and RNA Synthesis

    PubMed Central

    Lee, Wai-Ming; Ishikawa, Masayuki; Ahlquist, Paul

    2001-01-01

    All positive-strand RNA viruses assemble their RNA replication complexes on intracellular membranes. Brome mosaic virus (BMV) replicates its RNA in endoplasmic reticulum (ER)-associated complexes in plant cells and the yeast Saccharomyces cerevisiae. BMV encodes RNA replication factors 1a, with domains implicated in RNA capping and helicase functions, and 2a, with a central polymerase-like domain. Factor 1a interacts independently with the ER membrane, viral RNA templates, and factor 2a to form RNA replication complexes on the perinuclear ER. We show that BMV RNA replication is severely inhibited by a mutation in OLE1, an essential yeast chromosomal gene encoding Δ9 fatty acid desaturase, an integral ER membrane protein and the first enzyme in unsaturated fatty acid synthesis. OLE1 deletion and medium supplementation show that BMV RNA replication requires unsaturated fatty acids, not the Ole1 protein, and that viral RNA replication is much more sensitive than yeast growth to reduced unsaturated fatty acid levels. In ole1 mutant yeast, 1a still becomes membrane associated, recruits 2a to the membrane, and recognizes and stabilizes viral RNA templates normally. However, RNA replication is blocked prior to initiation of negative-strand RNA synthesis. The results show that viral RNA synthesis is highly sensitive to lipid composition and suggest that proper membrane fluidity or plasticity is essential for an early step in RNA replication. The strong unsaturated fatty acid dependence also demonstrates that modulating fatty acid balance can be an effective antiviral strategy. PMID:11160714

  11. Serum Fatty Acids, Desaturase Activities and Abdominal Obesity – A Population-Based Study of 60-Year Old Men and Women

    PubMed Central

    Alsharari, Zayed D.; Risérus, Ulf; Leander, Karin; Sjögren, Per; Carlsson, Axel C.; Vikström, Max; Laguzzi, Federica; Gigante, Bruna; Cederholm, Tommy; De Faire, Ulf; Hellénius, Mai-Lis

    2017-01-01

    Abdominal obesity is a key contributor of metabolic disease. Recent trials suggest that dietary fat quality affects abdominal fat content, where palmitic acid and linoleic acid influence abdominal obesity differently, while effects of n-3 polyunsaturated fatty acids are less studied. Also, fatty acid desaturation may be altered in abdominal obesity. We aimed to investigate cross-sectional associations of serum fatty acids and desaturases with abdominal obesity prevalence in a population-based cohort study. Serum cholesteryl ester fatty acids composition was measured by gas chromatography in 60-year old men (n = 1883) and women (n = 2015). Cross-sectional associations of fatty acids with abdominal obesity prevalence and anthropometric measures (e.g., sagittal abdominal diameter) were evaluated in multivariable-adjusted logistic and linear regression models, respectively. Similar models were employed to investigate relations between desaturase activities (estimated by fatty acid ratios) and abdominal obesity. In logistic regression analyses, palmitic acid, stearoyl-CoA-desaturase and Δ6-desaturase indices were associated with abdominal obesity; multivariable-adjusted odds ratios (95% confidence intervals) for highest versus lowest quartiles were 1.45 (1.19–1.76), 4.06 (3.27–5.05), and 3.07 (2.51–3.75), respectively. Linoleic acid, α-linolenic acid, docohexaenoic acid, and Δ5-desaturase were inversely associated with abdominal obesity; multivariable-adjusted odds ratios (95% confidence intervals): 0.39 (0.32–0.48), 0.74 (0.61–0.89), 0.76 (0.62–0.93), and 0.40 (0.33–0.49), respectively. Eicosapentaenoic acid was not associated with abdominal obesity. Similar results were obtained from linear regression models evaluating associations with different anthropometric measures. Sex-specific and linear associations were mainly observed for n3-polyunsaturated fatty acids, while associations of the other exposures were generally non-linear and similar across

  12. Susceptibility of podocytes to palmitic acid is regulated by stearoyl-CoA desaturases 1 and 2.

    PubMed

    Sieber, Jonas; Weins, Astrid; Kampe, Kapil; Gruber, Stefan; Lindenmeyer, Maja T; Cohen, Clemens D; Orellana, Jana M; Mundel, Peter; Jehle, Andreas W

    2013-09-01

    Type 2 diabetes mellitus is characterized by dyslipidemia with elevated free fatty acids (FFAs). Loss of podocytes is a hallmark of diabetic nephropathy, and podocytes are highly susceptible to saturated FFAs but not to protective, monounsaturated FFAs. We report that patients with diabetic nephropathy develop alterations in glomerular gene expression of enzymes involved in fatty acid metabolism, including induction of stearoyl-CoA desaturase (SCD)-1, which converts saturated to monounsaturated FFAs. By IHC of human renal biopsy specimens, glomerular SCD-1 induction was observed in podocytes of patients with diabetic nephropathy. Functionally, the liver X receptor agonists TO901317 and GW3965, two known inducers of SCD, increased Scd-1 and Scd-2 expression in cultured podocytes and reduced palmitic acid-induced cell death. Similarly, overexpression of Scd-1 attenuated palmitic acid-induced cell death. The protective effect of TO901317 was associated with a reduction of endoplasmic reticulum stress. It was lost after gene silencing of Scd-1/-2, thereby confirming that the protective effect of TO901317 is mediated by Scd-1/-2. TO901317 also shifted palmitic acid-derived FFAs into biologically inactive triglycerides. In summary, SCD-1 up-regulation in diabetic nephropathy may be part of a protective mechanism against saturated FFA-derived toxic metabolites that drive endoplasmic reticulum stress and podocyte death.

  13. Stearoyl-CoA Desaturase-1: Is It the Link between Sulfur Amino Acids and Lipid Metabolism?

    PubMed

    Poloni, Soraia; Blom, Henk J; Schwartz, Ida V D

    2015-06-03

    An association between sulfur amino acids (methionine, cysteine, homocysteine and taurine) and lipid metabolism has been described in several experimental and population-based studies. Changes in the metabolism of these amino acids influence serum lipoprotein concentrations, although the underlying mechanisms are still poorly understood. However, recent evidence has suggested that the enzyme stearoyl-CoA desaturase-1 (SCD-1) may be the link between these two metabolic pathways. SCD-1 is a key enzyme for the synthesis of monounsaturated fatty acids. Its main substrates C16:0 and C18:0 and products palmitoleic acid (C16:1) and oleic acid (C18:1) are the most abundant fatty acids in triglycerides, cholesterol esters and membrane phospholipids. A significant suppression of SCD-1 has been observed in several animal models with disrupted sulfur amino acid metabolism, and the activity of SCD-1 is also associated with the levels of these amino acids in humans. This enzyme also appears to be involved in the etiology of metabolic syndromes because its suppression results in decreased fat deposits (regardless of food intake), improved insulin sensitivity and higher basal energy expenditure. Interestingly, this anti-obesogenic phenotype has also been described in humans and animals with sulfur amino acid disorders, which is consistent with the hypothesis that SCD-1 activity is influenced by these amino acids, in particularly cysteine, which is a strong and independent predictor of SCD-1 activity and fat storage. In this narrative review, we discuss the evidence linking sulfur amino acids, SCD-1 and lipid metabolism.

  14. Quantitative trait loci mapping for conjugated linoleic acid, vaccenic acid and ∆(9) -desaturase in Italian Brown Swiss dairy cattle using selective DNA pooling.

    PubMed

    Strillacci, M G; Frigo, E; Canavesi, F; Ungar, Y; Schiavini, F; Zaniboni, L; Reghenzani, L; Cozzi, M C; Samoré, A B; Kashi, Y; Shimoni, E; Tal-Stein, R; Soller, M; Lipkin, E; Bagnato, A

    2014-08-01

    A selective DNA pooling approach was applied to identify QTL for conjugated linoleic acid (CLA), vaccenic acid (VA) and Δ(9) -desaturase (D9D) milk content in Italian Brown Swiss dairy cattle. Milk samples from 60 animals with higher values (after correction for environmental factors) and 60 animals with lower values for each of these traits from each of five half-sib families were pooled separately. The pools were genotyped using the Illumina BovineSNP50 BeadChip. Sire allele frequencies were compared between high and low tails at the sire and marker level for SNPs for which the sires were heterozygous. An r procedure was implemented to perform data analysis in a selective DNA pooling design. A correction for multiple tests was applied using the proportion of false positives among all test results. BTA 19 showed the largest number of markers in association with CLA. Associations between SNPs and the VA and Δ(9) -desaturase traits were found on several chromosomes. A bioinformatics survey identified genes with an important role in pathways for milk fat and fatty acids metabolism within 1 Mb of SNP markers associated with fatty acids contents.

  15. Cytoprotective Effects and Mechanisms of Δ-17 Fatty Acid Desaturase in Injured Human Umbilical Vein Endothelial Cells (HUVECs).

    PubMed

    Zhou, Haoyu; Wang, Chengming

    2017-04-04

    BACKGROUND The beneficial effect of Δ-17 FAD is poorly understood. The aim of this study was to investigate the protective mechanism of fatty acids against atherosclerotic (AS) damage induced by oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs), and to identify the molecular mechanisms involved. MATERIAL AND METHODS The ox-LDL was used to induce lipotoxicity in HUVECs to establish a model of oxidative injury. HUVECs were transfected with Δ-17FAD lentivirus to induce cytoprotective effects. We evaluated the alterations in cell proliferation and apoptosis, and oxidative stress index, including levels of nitric oxide (NO), malonyldialdehyde (MDA), SOD enzyme, LDH, GSH-PX, and vascular endothelial growth factor (VEGF) expression. RESULTS The ox-LDL-induced excessive cellular apoptosis of HUVECs was abrogated by upregulation of Δ-17 FAD. Importantly, Δ-17 FAD converted ω-3 polyunsaturated fatty acid ARA into ω-6 polyunsaturated fatty acid EPA. Further, Δ-17 FAD overexpression promoted the proliferation of HUVECS, and inhibited ox-LDL-induced lipid peroxidation of HUVECs. The levels of nitric oxide, GSH-PX, and SOD enzyme were increased, and the activity of MDA and LDH was suppressed by the upregulation of Δ-17 FAD. In addition, upregulation of Δ-17 FAD significantly increased VEGF expression. In vitro tube formation assay showed that Δ-17 FAD significantly promoted angiogenesis. CONCLUSIONS These results suggest that Δ-17 fatty acid desaturase plays a beneficial role in the prevention of ox-LDL-induced cellular damage.

  16. Cytoprotective Effects and Mechanisms of Δ-17 Fatty Acid Desaturase in Injured Human Umbilical Vein Endothelial Cells (HUVECs)

    PubMed Central

    Zhou, Haoyu; Wang, Chengming

    2017-01-01

    Background The beneficial effect of Δ-17 FAD is poorly understood. The aim of this study was to investigate the protective mechanism of fatty acids against atherosclerotic (AS) damage induced by oxidized low-density lipoprotein (ox-LDL) in human umbilical vein endothelial cells (HUVECs), and to identify the molecular mechanisms involved. Material/Methods The ox-LDL was used to induce lipotoxicity in HUVECs to establish a model of oxidative injury. HUVECs were transfected with Δ-17FAD lentivirus to induce cytoprotective effects. We evaluated the alterations in cell proliferation and apoptosis, and oxidative stress index, including levels of nitric oxide (NO), malonyldialdehyde (MDA), SOD enzyme, LDH, GSH-PX, and vascular endothelial growth factor (VEGF) expression. Results The ox-LDL-induced excessive cellular apoptosis of HUVECs was abrogated by upregulation of Δ-17 FAD. Importantly, Δ-17 FAD converted ω-3 polyunsaturated fatty acid ARA into ω-6 polyunsaturated fatty acid EPA. Further, Δ-17 FAD overexpression promoted the proliferation of HUVECS, and inhibited ox-LDL-induced lipid peroxidation of HUVECs. The levels of nitric oxide, GSH-PX, and SOD enzyme were increased, and the activity of MDA and LDH was suppressed by the upregulation of Δ-17 FAD. In addition, upregulation of Δ-17 FAD significantly increased VEGF expression. In vitro tube formation assay showed that Δ-17 FAD significantly promoted angiogenesis. Conclusions These results suggest that Δ-17 fatty acid desaturase plays a beneficial role in the prevention of ox-LDL-induced cellular damage. PMID:28373637

  17. Gamma-linolenic acid dietary supplementation can reverse the aging influence on rat liver microsome delta 6-desaturase activity.

    PubMed

    Biagi, P L; Bordoni, A; Hrelia, S; Celadon, M; Horrobin, D F

    1991-05-08

    We have recently demonstrated that in rats the process of delta 6-desaturation of linoleic and alpha-linolenic acids slows with aging. One method of counteracting the effect of slowed desaturation of linoleic acid would be to provide the 6-desaturated metabolite, gamma-linolenic acid (18:3(n-6) GLA) directly. We have here investigated the 6-desaturation of both linoleic and alpha-linolenic acids in liver microsomes of young and old rats given GLA in the form of evening primrose oil (EPO) (B diet) in comparison to animals given soy bean oil alone (A diet), monitoring also the fatty acid composition of liver microsomes and relating this to the microviscosity of the membranes. In young rats the different experimental diets did not produce any difference in delta 6-desaturase (D6D) activity on either substrate suggesting that, when D6D activity is at or near its peak, the variations in diet tested are unable to influence it. In the old animals the rate of 6-desaturation of linoleic and particularly of alpha-linolenic acid was significantly greater in the B diet fed animals than in the A diet fed. The effects of the diets on the fatty acid composition of liver microsomes were consistent with the findings with regard to 6-desaturation. Administration of GLA partially corrected the abnormalities of n-6 essential fatty acid (EFA) metabolism by raising the concentration of 20:4(n-6) and other 6-desaturated EFAs. Furthermore, the GLA rich diet also increased the levels of dihomo-gamma-linolenic acid and of 6-desaturated n-3 EFAs in the liver microsomes. The microviscosity of microsomal membranes as indicated by DPH polarization was correlated with the unsaturation index of the same membranes. There was a very strong correlation between the two. In both young and old rats the B diet reduced the microviscosity and increased the unsaturation index. However, the effect was much greater in the old animals.

  18. Relationship between stearoyl-CoA desaturase 1 gene expression, relative protein abundance, and its fatty acid products in bovine tissues.

    PubMed

    Rezamand, Pedram; Watts, Jason S; Yavah, Katherine M; Mosley, Erin E; Ma, Liying; Corl, Benjamin A; McGuire, Mark A

    2014-08-01

    Stearoyl-CoA desaturase 1 (SCD1) greatly contributes to the unsaturated fatty acids present in milk and meat of cattle. The SCD1 enzyme introduces a double bond into certain saturated fatty acyl-CoAs producing monounsaturated fatty acids (MUFA). The SCD1 enzyme also has been shown to be active in the bovine mammary gland converting t11 18:1 (vaccenic acid) to c9 t11 conjugated linoleic acid (CLA). The objective of this study was to determine any association between the gene expression of SCD1 and occurrence of its products (c9 14:1, c9 16:1, c9 18:1, and c9 t11 18:2) in various bovine tissues. Tissue samples were obtained from lactating Holstein cows (n=28) at slaughter, frozen in liquid nitrogen and stored at -80 °C. Total RNA was extracted and converted to complementary DNA for quantitative real time polymerase chain reaction (PCR) analysis of the SCD1 gene. Extracted lipid was converted to fatty acid methyl esters and analysed by GC. Tissues varied in expression of SCD1 gene with mammary, cardiac, intestinal adipose, and skeletal muscle expressing greater copy number as compared with lung, large intestine, small intestine and liver (371, 369, 328, 286, 257, 145, 73, and 21 copies/ng RNA, respectively). Tissues with high mRNA expression of SCD1 contained greater SCD1 protein whereas detection of SCD1 protein in tissues with low SCD1 mRNA expression was very faint or absent. Across tissues, the desaturase indices for c9 18:1 (r=0.24) and sum of SCD products (r=0.20) were positively correlated with SCD1 gene expression (P<0.01 for both). Within each tissue, the relationship between SCD1 gene expression and the desaturase indices varied. No correlation was detected between SCD1 expression and desaturase indices in the liver, large and small intestines, lung, cardiac or skeletal muscles. Positive correlations, however, were detected between SCD1 expression and the desaturase indices in intestinal adipose tissue (P<0.02 for all) except 14:1, whereas only c9 18:1, c9

  19. Glycine betaine protects tomato (Solanum lycopersicum) plants at low temperature by inducing fatty acid desaturase7 and lipoxygenase gene expression.

    PubMed

    Karabudak, T; Bor, M; Özdemir, F; Türkan, İ

    2014-03-01

    Cold stress is among the environmental stressors limiting productivity, yield and quality of agricultural plants. Tolerance to cold stress is associated with the increased unsaturated fatty acids ratio in the plant membranes which are also known to be substrates of octadecanoid pathway for jasmonate and other oxylipins biosynthesis. Accumulation of osmoprotectant, glycine betaine (GB) is well known to be effective in the protecting membranes and mitigating cold stress effects but, the mode of action is poorly understood. We studied the role of GB in cold stress responses of two tomato cultivated varieties; Gerry (cold stress sensitive) and T47657 (moderately cold stress tolerant) and compared the differences in lypoxygenase-13 (TomLOXF) and fatty acid desaturase 7 (FAD7) gene expression profiles and physiological parameters including relative growth rates, relative water content, osmotic potential, photosynthetic efficiency, membrane leakage, lipid peroxidation levels. Our results indicated that GB might have a role in inducing FAD7 and LOX expressions for providing protection against cold stress in tomato plants which could be related to the desaturation process of lipids leading to increased membrane stability and/or induction of other genes related to stress defense mechanisms via octadecanoid pathway or lipid peroxidation products.

  20. Characterization of 19 Genes Encoding Membrane-Bound Fatty Acid Desaturases and their Expression Profiles in Gossypium raimondii Under Low Temperature.

    PubMed

    Liu, Wei; Li, Wei; He, Qiuling; Daud, Muhammad Khan; Chen, Jinhong; Zhu, Shuijin

    2015-01-01

    To produce unsaturated fatty acids, membrane-bound fatty acid desaturases (FADs) can be exploited to introduce double bonds into the acyl chains of fatty acids. In this study, 19 membrane-bound FAD genes were identified in Gossypium raimondii through database searches and were classified into four different subfamilies based on phylogenetic analysis. All 19 membrane-bound FAD proteins shared three highly conserved histidine boxes, except for GrFAD2.1, which lost the third histidine box in the C-terminal region. In the G. raimondii genome, tandem duplication might have led to the increasing size of the FAD2 cluster in the Omega Desaturase subfamily, whereas segmental duplication appeared to be the dominant mechanism for the expansion of the Sphingolipid and Front-end Desaturase subfamilies. Gene expression analysis showed that seven membrane-bound FAD genes were significantly up-regulated and that five genes were greatly suppressed in G. raimondii leaves exposed to low temperature conditions.

  1. Relationship between a Common Variant in the Fatty Acid Desaturase (FADS) Cluster and Eicosanoid Generation in Humans*

    PubMed Central

    Hester, Austin G.; Murphy, Robert C.; Uhlson, Charis J.; Ivester, Priscilla; Lee, Tammy C.; Sergeant, Susan; Miller, Leslie R.; Howard, Timothy D.; Mathias, Rasika A.; Chilton, Floyd H.

    2014-01-01

    Dramatic shifts in the Western diet have led to a marked increase in the dietary intake of the n-6 polyunsaturated fatty acid (PUFA), linoleic acid (LA). Dietary LA can then be converted to arachidonic acid (ARA) utilizing three enzymatic steps. Two of these steps are encoded for by the fatty acid desaturase (FADS) cluster (chromosome 11, 11q12.2-q13) and certain genetic variants within the cluster are highly associated with ARA levels. However, no study to date has examined whether these variants further influence pro-inflammatory, cyclooxygenase and lipoxygenase eicosanoid products. This study examined the impact of a highly influential FADS SNP, rs174537 on leukotriene, HETE, prostaglandin, and thromboxane biosynthesis in stimulated whole blood. Thirty subjects were genotyped at rs174537 (GG, n = 11; GT, n = 13; TT, n = 6), a panel of fatty acids from whole serum was analyzed, and precursor-to-product PUFA ratios were calculated as a marker of the capacity of tissues (particularly the liver) to synthesize long chain PUFAs. Eicosanoids produced by stimulated human blood were measured by LC-MS/MS. We observed an association between rs174537 and the ratio of ARA/LA, leukotriene B4, and 5-HETE but no effect on levels of cyclooxygenase products. Our results suggest that variation at rs174537 not only impacts the synthesis of ARA but the overall capacity of whole blood to synthesize 5-lipoxygenase products; these genotype-related changes in eicosanoid levels could have important implications in a variety of inflammatory diseases. PMID:24962583

  2. [The isozymes of stearil-coenzymeA-desaturase and insulin activity in the light of phylogenetic theory of pathology. Oleic fatty acid and realization of biologic functions of trophology and locomotion].

    PubMed

    2013-11-01

    The formation of function of isozymes of stearil-coenzymeA-desaturases occured at the different stages of phylogeny under realization of biologic function of trophology (stearil-coenzymeA-desaturase 1) and biologic function of locomotion, insulin system (stearil-coenzymeA-desaturase 2) billions years later. The stearil-coenzymeA-desaturase 1 transforms in C 18:1 oleic fatty acid only exogenous C 16:0 palmitinic saturated fatty acid. The stearil-coenzymeA-desaturase 2 transforms only endogenic palmitinic saturated fatty acid, synthesized form glucose. The biologic role of insulin is in energy support of biologic function of locomotion. Insulin through expressing stearil-coenzymeA-desaturase 2 transforms energetically non-optimal palmitinic variation of metabolism of substrates into highly effective oleic variation for cells' groundwork of energy (saturated fatty acid and mono fatty acid). The surplus of palmitinic saturated fatty acid in food is enabled in pathogenesis of resistance to insulin and derangement of synthesis of hormone by beta-cells of islets. The resistance to insulin and diabetes mellitus are primarily the derangement of metabolism of saturated fatty acids with mono fatty acids, energy problems of organism and only afterwards the derangement of metabolism of carbohydrates. It is desirable to restrict food intake of exogenous palmitinic saturated fatty acid. The reasons are low expression of independent of insulin stearil-coenzymeA-desaturase 2, marked lipotoxicity of polar form of palmitinic saturated fatty acid and synthesis of non-optimal palmitinic triglycerides instead of physiologic and more energetically more effective oleic triglycerides.

  3. Delta 6- and delta 12-desaturase activities and phosphatidic acid formation in microsomal preparations from the developing cotyledons of common borage (Borago officinalis).

    PubMed Central

    Griffiths, G; Stobart, A K; Stymne, S

    1988-01-01

    Microsomal membrane preparations from the maturing cotyledons of common borage (Borago officinalis) exhibit delta 12- and delta 6-desaturase activities, which resulted in the synthesis of linoleate and gamma-linolenate respectively. The desaturase enzymes utilized the complex lipid substrate phosphatidylcholine. The activity of these enzymes was sufficiently high to allow the monitoring of the mass changes in the endogenous oleate, linoleate and gamma-linolenate in the microsomal phosphatidylcholine in the presence of NADH (i.e. under desaturating conditions). The results illustrate that the delta 12-desaturase uses the oleate substrate at both the sn-1 and -2 positions of sn-phosphatidylcholine, whereas the delta 6-desaturase is almost totally restricted to the linoleate at position 2 of the complex lipid. Estimate of the acyl-substrate pool size at position 2 of sn-phosphatidylcholine for both desaturases indicated that some 50% of the oleate and linoleate was available to the enzymes. The microsomes (microsomal fractions) had a somewhat impaired Kennedy [(1961) Fed. Proc. Fed. Am. Soc. Exp. Biol. 20, 934-940] pathway for the formation of triacylglycerols when compared with other oil-rich plant species that have been studied [Stymne & Stobart (1987) The Biochemistry of Plants: a Comprehensive Treatise (Stumpf, P.K., ed.), vol. 10, chapter 8, pp. 175-214, Academic Press, New York]. In the presence of sn-glycerol 3-phosphate and acyl-CoA, large quantities of phosphatidic acid accumulated in the membranes. Acyl-selectivity studies on the glycerol-acylating enzymes showed that gamma-linolenate could be acylated to both the sn-1 and sn-2 positions of sn-glycerol 3-phosphate. However, stereochemical analysis of the acyl components of the sn-triacylglycerol obtained from mature seeds indicated that, whereas no gamma-linolenate was present at the sn-1 position, it accounted for over 50% of the fatty acids at position sn-3. The results indicate that the diacylglycerol

  4. Delta 6- and delta 12-desaturase activities and phosphatidic acid formation in microsomal preparations from the developing cotyledons of common borage (Borago officinalis).

    PubMed

    Griffiths, G; Stobart, A K; Stymne, S

    1988-06-15

    Microsomal membrane preparations from the maturing cotyledons of common borage (Borago officinalis) exhibit delta 12- and delta 6-desaturase activities, which resulted in the synthesis of linoleate and gamma-linolenate respectively. The desaturase enzymes utilized the complex lipid substrate phosphatidylcholine. The activity of these enzymes was sufficiently high to allow the monitoring of the mass changes in the endogenous oleate, linoleate and gamma-linolenate in the microsomal phosphatidylcholine in the presence of NADH (i.e. under desaturating conditions). The results illustrate that the delta 12-desaturase uses the oleate substrate at both the sn-1 and -2 positions of sn-phosphatidylcholine, whereas the delta 6-desaturase is almost totally restricted to the linoleate at position 2 of the complex lipid. Estimate of the acyl-substrate pool size at position 2 of sn-phosphatidylcholine for both desaturases indicated that some 50% of the oleate and linoleate was available to the enzymes. The microsomes (microsomal fractions) had a somewhat impaired Kennedy [(1961) Fed. Proc. Fed. Am. Soc. Exp. Biol. 20, 934-940] pathway for the formation of triacylglycerols when compared with other oil-rich plant species that have been studied [Stymne & Stobart (1987) The Biochemistry of Plants: a Comprehensive Treatise (Stumpf, P.K., ed.), vol. 10, chapter 8, pp. 175-214, Academic Press, New York]. In the presence of sn-glycerol 3-phosphate and acyl-CoA, large quantities of phosphatidic acid accumulated in the membranes. Acyl-selectivity studies on the glycerol-acylating enzymes showed that gamma-linolenate could be acylated to both the sn-1 and sn-2 positions of sn-glycerol 3-phosphate. However, stereochemical analysis of the acyl components of the sn-triacylglycerol obtained from mature seeds indicated that, whereas no gamma-linolenate was present at the sn-1 position, it accounted for over 50% of the fatty acids at position sn-3. The results indicate that the diacylglycerol

  5. [A method using long primers for cloning the upstream sequence of delta-6 fatty acid desaturases gene of Thamnidium elegans by nested inverse PCR].

    PubMed

    Wang, De-Pei; Sun, Wei; Li, Ming-Chun; Wei, Dong-Sheng; Zhang, Ying-Hui; Xing, Lai-Jun

    2006-07-01

    Thamnidium elegans is a kind of phycomycete that produces essential unsaturated fatty acids, particularly y-linolenic acid. In this process, delta6-Fatty acid desaturase (D6D) plays a key role due to its enzymatic properties that catalyze the delta6 site dehydrogenation of precursor linoleic acid (18:2delta(9, 12) n-6) and a-linolenic acid (18:3delta(9, 12, 15) n-3). This reaction is the first and rate-limiting step of highly unsaturated fatty acids (HUFA) synthesis pathways. After we have isolated and cloned the gene coding delta6-fatty acid desaturase from Thamnidium elegans As3.2806 (GenBank accession number DQ099380), our interest focuses on the promotion and regulation of the gene transcription. To achieve this aim, we designed long primers and used nested inverse PCR to amplify DNA flanking sequences. First, genome of Thamnidium elegans was extracted and digested with restriction enzymes EcoR I and Kpn I , respectively. Then we ligated the digested DNA with T4 ligase at low concentration which is propitious for linear DNA to joint intromolecule. According to the sequence of delta6-fatty acid desaturase gene of Thamnidium elegans, we designed a couple of 35nt long inverse primers and two couples of shorter inverse primers for inverse PCR. Three rounds of PCR reactions were performed. In the primary reaction, the ligated DNA was used as a template, and the product was used as the template of the secondary reaction, the tertiary reaction was achieved in the same way. After all the three rounds of reactions, we got a nice product about 4 kb from the EcoR I digested sample, in which a 1.3kb 5' upstream sequence (GenBank accession number DQ309425) of delta6-fatty acid desaturase gene containing several putative regulatory elements including TATA. box, FSE-2, AP-1 sites, CCAAT cis-element site and STRE-binding site was derived after sequencing. All of these implied intensely that this 1.3kb fragment is a condition-regulated promoter. It is the first report about

  6. Biosynthesis of Polyunsaturated Fatty Acids in Octopus vulgaris: Molecular Cloning and Functional Characterisation of a Stearoyl-CoA Desaturase and an Elongation of Very Long-Chain Fatty Acid 4 Protein

    PubMed Central

    Monroig, Óscar; de Llanos, Rosa; Varó, Inmaculada; Hontoria, Francisco; Tocher, Douglas R.; Puig, Sergi; Navarro, Juan C.

    2017-01-01

    Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed the Octopus vulgaris Scd is a ∆9 desaturase with relatively high affinity towards saturated FAs with ≥ C18 chain lengths. Scd was unable to desaturate 20:1n-15 (∆520:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at ∆9 position. Interestingly, the previously characterised ∆5 fatty acyl desaturase was indeed able to convert 20:1n-9 (∆1120:1) to ∆5,1120:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs. PMID:28335553

  7. Expression of a delta 9 14:0-acyl carrier protein fatty acid desaturase gene is necessary for the production of omega 5 anacardic acids found in pest-resistant geranium (Pelargonium xhortorum).

    PubMed Central

    Schultz, D J; Cahoon, E B; Shanklin, J; Craig, R; Cox-Foster, D L; Mumma, R O; Medford, J I

    1996-01-01

    Anacardic acids, a class of secondary compounds derived from fatty acids, are found in a variety of dicotyledonous families. Pest resistance (e.g., spider mites and aphids) in Pelargonium xhortorum (geranium) is associated with high levels (approximately 81%) of unsaturated 22:1 omega 5 and 24:1 omega 5 anacardic acids in the glandular trichome exudate. A single dominant locus controls the production of these omega 5 anacardic acids, which arise from novel 16:1 delta 11 and 18:1 delta 13 fatty acids. We describe the isolation and characterization of a cDNA encoding a unique delta 9 14:0-acyl carrier protein fatty acid desaturase. Several lines of evidence indicated that expression of this desaturase leads to the production of the omega 5 anacardic acids involved in pest resistance. First, its expression was found in pest-resistant, but not suspectible, plants and its expression followed the production of the omega 5 anacardic acids in segregating populations. Second, its expression and the occurrence of the novel 16:1 delta 11 and 18:1 delta 13 fatty acids and the omega 5 anacardic acids were specific to tall glandular trichomes. Third, assays of the recombinant protein demonstrated that this desaturase produced the 14:1 delta 9 fatty acid precursor to the novel 16:1 delta 11 and 18:1 delta 13 fatty acids. Based on our genetic and biochemical studies, we conclude that expression of this delta 9 14:0-ACP desaturase gene is required for the production of omega 5 anacardic acids that have been shown to be necessary for pest resistance in geranium. Images Fig. 1 Fig. 3 Fig. 5 PMID:8710947

  8. Computer Simulation Model for the Biosynthesis of Galactosyldiacylglycerols and Fatty Acid Desaturation in Plants (Determination of Rates of Desaturase Activity in Monogalactosyldiacylglycerol).

    PubMed Central

    Williams, J. P.; Khan, M. U.; Wong, D.

    1993-01-01

    The level of unsaturation of the constituent fatty acids of many glycerolipids in plant membranes is modified by environmental factors. The measurement of the rate of the desaturation of these fatty acids is essential to an understanding of how plants adapt to changing environments. This is difficult because of the complexity of the system and the problems involved in measuring rates of these enzyme reactions in cell-free preparations. A computer program has been developed that simulates the synthesis of galactosyldiacylglycerols and desaturation of their fatty acids in chloroplasts. The program uses the rate of incorporation and distribution of 14C in fatty acids after 14CO2 feeding to estimate rates of desaturation in the fatty acids of glycerolipids. Data are presented to demonstrate the use of the program in comparing rates of desaturation in the five enzyme reactions associated with monogalactosyldiacylglycerol in the chloroplastic pathway of leaves from Brassica napus. The method represents a quick, reliable, and accurate measure of desaturase activity in vivo and is the only method available to estimate desaturase activity of all five enzymes at the same time. PMID:12231750

  9. Development and characterization of low α-linolenic acid Brassica oleracea lines bearing a novel mutation in a ‘class a’ FATTY ACID DESATURASE 3 gene

    PubMed Central

    2014-01-01

    Background Traditional canola (Brassica napus L.; AACC, 2n = 38) cultivars yield seed oil with a relatively high proportion of α-linolenic acid (ALA; C18:3cis∆9,12,15), which is desirable from a health perspective. Unfortunately, due to the instability of this fatty acid, elevated levels also result in oils that exhibit a short shelf life and problems associated with use at high temperatures. As a result, the development of cultivars bearing reduced amounts of ALA in their seeds is becoming a priority. To date, several low ALA B. napus cultivars (~2-3% ALA of total fatty acids) have been developed and molecular analyses have revealed that the low ALA phenotype of lines tested thus far is a result of mutations within two ‘class b’ FATTY ACID DESATURASE 3 (FAD3) genes. Since B. napus possesses six FAD3 genes (two ‘class a’, two ‘class b’ and two ‘class c’) and ALA levels of approximately 2-3% remain in these low ALA lines, it is likely that the mutation of additional FAD3 genes could further decrease the content of this fatty acid. Results In this study, we generated low ALA (≤2%) lines of B. oleracea, which is the C genome progenitor species of B. napus, via ethyl methanesulphonate (EMS) mutagenesis. We identified a novel nonsense mutation within the ‘class a’ FAD3 gene (BoFAD3-2) in these lines, which would result in the production of an encoded protein lacking 110 amino acids at its C terminus. When expressed in Saccharomyces cerevisiae, this mutant protein exhibited a drastic decline in its Δ-15 desaturase activity compared to the wild-type (wt) protein. Furthermore, we demonstrated that the expression of the mutant BoFAD3-2 gene was significantly reduced in developing seeds of low ALA lines when compared to expression in wt plants. Conclusions Given the additive nature of FAD3 mutations on ALA content and the ease with which B. napus can be re-synthesized from its progenitor species, the mutant isolated here has the potential to be

  10. Effect of tanniniferous Terminalia chebula extract on rumen biohydrogenation, ∆(9)-desaturase activity, CLA content and fatty acid composition in longissimus dorsi muscle of kids.

    PubMed

    Rana, Madhu Suman; Tyagi, A; Hossain, Sk Asraf; Tyagi, A K

    2012-03-01

    Conjugated linoleic acid, a fatty acid found in milk fat and ruminant meat is one of the functional food components. Modifying fatty acid composition so as to increase CLA and other beneficial PUFA/MUFA level and reducing SFA levels might be a key to enhance the neutraceutical and therapeutic value of ruminant-derived food products. In the present experiment, the effect of supplementation of polyphenol rich Terminalia chebula plant extract at different concentrations (1.06g/kg and 3.18g/kg of body weight in T1 and T2 groups, respectively) was investigated on fatty acid composition of rumen fluid, plasma, intramuscular fat and Δ9-desaturase activity in longissimus dorsi muscle of crossbred kids. Total MUFA and PUFA content in muscle were enhanced by 25 and 35%, respectively, whereas SFA was reduced by 20% thereby improving the desaturation index. Δ9-desaturase activity also increased by 47% resulting in an enhancement of total CLA content (58.73%) in muscle.

  11. Genome-wide analysis of the omega-3 fatty acid desaturase gene family in Gossypium

    SciTech Connect

    Yurchenko, Olga P.; Park, Sunjung; Ilut, Daniel C.; Inmon, Jay J.; Millhollon, Jon C.; Liechty, Zach; Page, Justin T.; Jenks, Matthew A.; Chapman, Kent D.; Udall, Joshua A.; Gore, Michael A.; Dyer, John M.

    2014-11-18

    The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid tropical and subtropical regions, and thus perform well in these geographical areas, cotton seedlings are sensitive to cold temperature, which can significantly reduce crop yields. One of the common biochemical responses of plants to cold temperatures is an increase in omega-3 fatty acids, which protects cellular function by maintaining membrane integrity. The purpose of our study was to identify and characterize the omega-3 fatty acid desaturase (FAD) gene family in G. hirsutum, with an emphasis on identifying omega-3 FADs involved in cold temperature adaptation. Results: Eleven omega-3 FAD genes were identified in G. hirsutum, and characterization of the gene family in extant A and D diploid species (G. herbaceum and G. raimondii, respectively) allowed for unambiguous genome assignment of all homoeologs in tetraploid G. hirsutum. The omega-3 FAD family of cotton includes five distinct genes, two of which encode endoplasmic reticulum-type enzymes (FAD3-1 and FAD3-2) and three that encode chloroplast-type enzymes (FAD7/8-1, FAD7/8-2, and FAD7/8-3). The FAD3-2 gene was duplicated in the A genome progenitor species after the evolutionary split from the D progenitor, but before the interspecific hybridization event that gave rise to modern tetraploid cotton. RNA-seq analysis revealed conserved, gene-specific expression patterns in various organs and cell types and semi-quantitative RT-PCR further revealed that FAD7/8-1 was specifically induced during cold temperature treatment of G. hirsutum seedlings. Conclusions: The omega-3 FAD gene family in cotton was characterized at the genome-wide level

  12. A Functional Variant in the Stearoyl-CoA Desaturase Gene Promoter Enhances Fatty Acid Desaturation in Pork

    PubMed Central

    Estany, Joan; Ros-Freixedes, Roger; Tor, Marc; Pena, Ramona N.

    2014-01-01

    There is growing public concern about reducing saturated fat intake. Stearoyl-CoA desaturase (SCD) is the lipogenic enzyme responsible for the biosynthesis of oleic acid (18∶1) by desaturating stearic acid (18∶0). Here we describe a total of 18 mutations in the promoter and 3′ non-coding region of the pig SCD gene and provide evidence that allele T at AY487830:g.2228T>C in the promoter region enhances fat desaturation (the ratio 18∶1/18∶0 in muscle increases from 3.78 to 4.43 in opposite homozygotes) without affecting fat content (18∶0+18∶1, intramuscular fat content, and backfat thickness). No mutations that could affect the functionality of the protein were found in the coding region. First, we proved in a purebred Duroc line that the C-T-A haplotype of the 3 single nucleotide polymorphisms (SNPs) (g.2108C>T; g.2228T>C; g.2281A>G) of the promoter region was additively associated to enhanced 18∶1/18∶0 both in muscle and subcutaneous fat, but not in liver. We show that this association was consistent over a 10-year period of overlapping generations and, in line with these results, that the C-T-A haplotype displayed greater SCD mRNA expression in muscle. The effect of this haplotype was validated both internally, by comparing opposite homozygote siblings, and externally, by using experimental Duroc-based crossbreds. Second, the g.2281A>G and the g.2108C>T SNPs were excluded as causative mutations using new and previously published data, restricting the causality to g.2228T>C SNP, the last source of genetic variation within the haplotype. This mutation is positioned in the core sequence of several putative transcription factor binding sites, so that there are several plausible mechanisms by which allele T enhances 18∶1/18∶0 and, consequently, the proportion of monounsaturated to saturated fat. PMID:24465944

  13. Down-regulation of crambe fatty acid desaturase and elongase in Arabidopsis and crambe resulted in significantly increased oleic acid content in seed oil.

    PubMed

    Li, Xueyuan; Mei, Desheng; Liu, Qing; Fan, Jing; Singh, Surinder; Green, Allan; Zhou, Xue-Rong; Zhu, Li-Hua

    2016-01-01

    High oleic oil is an important industrial feedstock that has been one of the main targets for oil improvement in a number of oil crops. Crambe (Crambe abyssinica) is a dedicated oilseed crop, suitable for industrial oil production. In this study, we down-regulated the crambe fatty acid desaturase (FAD) and fatty acid elongase (FAE) genes for creating high oleic seed oil. We first cloned the crambe CaFAD2, CaFAD3 and CaFAE1 genes. Multiple copies of each of these genes were isolated, and the highly homologous sequences were used to make RNAi constructs. These constructs were first tested in Arabidopsis, which led to the elevated oleic or linoleic levels depending on the genes targeted, indicating that the RNAi constructs were effective in regulating the expression of the target genes in nonidentical but closely related species. Furthermore, down-regulation of CaFAD2 and CaFAE1 in crambe with the FAD2-FAE1 RNAi vector resulted in even more significant increase in oleic acid level in the seed oil with up to 80% compared to 13% for wild type. The high oleic trait has been stable in subsequent five generations and the GM line grew normally in greenhouse. This work has demonstrated the great potential of producing high oleic oil in crambe, thus contributing to its development into an oil crop platform for industrial oil production.

  14. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco.

    PubMed

    Sayanova, O; Smith, M A; Lapinskas, P; Stobart, A K; Dobson, G; Christie, W W; Shewry, P R; Napier, J A

    1997-04-15

    gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5.

  15. In Situ Molecular Identification of the Plastid ω3 Fatty Acid Desaturase FAD7 from Soybean: Evidence of Thylakoid Membrane Localization1

    PubMed Central

    Andreu, Vanesa; Collados, Raquel; Testillano, Pilar S.; Risueño, María del Carmen; Picorel, Rafael; Alfonso, Miguel

    2007-01-01

    ω3 fatty acid desaturases are the enzymes responsible for the synthesis of trienoic fatty acids in plants. These enzymes have been mainly investigated using molecular, biochemical, and genetic approaches but very little is known about their subcellular distribution in plant cells. In this work, the precise subcellular localization of the ω3 desaturase FAD7 was elucidated by immunofluorescence and immunogold labeling using a monospecific GmFAD7 polyclonal antibody in soybean (Glycine max) photoautotrophic cell suspension cultures. Confocal analysis revealed the localization of the GmFAD7 protein within the chloroplast; i.e. signals from FAD7 and chlorophyll autofluorescence showed specific colocalization. Immunogold labeling was pursued on cryofixed and freeze-substituted samples for convenient preservation of antigenicity and ultrastructure of membrane subcompartments. Our data revealed that the FAD7 protein was preferentially localized in the thylakoid membranes. Biochemical fractionation of purified chloroplasts and western analysis of the subfractions further confirmed these results. These findings suggest that not only the envelope, but also the thylakoid membranes could be sites of lipid desaturation in higher plants. PMID:17951449

  16. Plasma fatty acid composition, estimated desaturase activities, and intakes of energy and nutrient in Japanese men with abdominal obesity or metabolic syndrome.

    PubMed

    Kawashima, Aiko; Sugawara, Shiori; Okita, Misako; Akahane, Takemi; Fukui, Kennichi; Hashiuchi, Maiko; Kataoka, Chieko; Tsukamoto, Ikuyo

    2009-01-01

    To examine predictive factors for abdominal obesity or metabolic syndrome, we investigated the association of plasma fatty acid composition, estimated desaturase activity, and nutrient intakes, with abdominal obesity or metabolic syndrome in Japanese males. Clinical characteristics, the fatty acid composition of plasma cholesteryl esters, and energy and nutrient intakes were analyzed in 3 groups: metabolic syndrome (MS, n=24), abdominal obesity (OB, n=43), and control (n=27). The estimated desaturase activities were calculated by the ratio of 16:1n-7/16:0, 18:3n-6/18:2n-6, and 20:4n-6/20:3n-6 in plasma cholesteryl esters as surrogates of the measure of the delta 9, delta 6, delta 5 desaturase (D9-16D, D6D and D5D) activities, respectively. Plasma fatty acid composition did not differ significantly between the OB group and the control group. The MS group had higher levels of palmitoleic, oleic, and gamma-linolenic acids, but a lower level of linoleic acid than the control. Stronger D6D activity and weaker D5D activity were observed in the OB group. A higher level of D9-16D activity as well as a higher level of D6D activity and a lower level of D5D activity was observed in the MS group. A logistic regression analysis showed that the low D5D activity and high D9-16D activity were predictive of the development of abdominal obesity from controls (odds ratio=0.39, p<0.05) and metabolic syndrome from abdominal obesity (odds ratio=2.44, p<0.05), respectively. In the multiple linear regression analysis, D5D activity positively correlated with the intake of eicosapentaenoic acid (EPA). In conclusion, the estimated D5D activity was a predictive factor for abdominal obesity and the estimated D9-16D activity was a predictive factor for developing metabolic syndrome from abdominal obesity in Japanese male subjects. Dietary intake of EPA would play an important role in preventing abdominal obesity and the development of metabolic syndrome.

  17. Suppression of the rice fatty-acid desaturase gene OsSSI2 enhances resistance to blast and leaf blight diseases in rice.

    PubMed

    Jiang, Chang-Jie; Shimono, Masaki; Maeda, Satoru; Inoue, Haruhiko; Mori, Masaki; Hasegawa, Morifumi; Sugano, Shoji; Takatsuji, Hiroshi

    2009-07-01

    Fatty acids and their derivatives play important signaling roles in plant defense responses. It has been shown that suppressing a gene for stearoyl acyl carrier protein fatty-acid desaturase (SACPD) enhances the resistance of Arabidopsis (SSI2) and soybean to multiple pathogens. In this study, we present functional analyses of a rice homolog of SSI2 (OsSSI2) in disease resistance of rice plants. A transposon insertion mutation (Osssi2-Tos17) and RNAi-mediated knockdown of OsSSI2 (OsSSI2-kd) reduced the oleic acid (18:1) level and increased that of stearic acid (18:0), indicating that OsSSI2 is responsible for fatty-acid desaturase activity. These plants displayed spontaneous lesion formation in leaf blades, retarded growth, slight increase in endogenous free salicylic acid (SA) levels, and SA/benzothiadiazole (BTH)-specific inducible genes, including WRKY45, a key regulator of SA/BTH-induced resistance, in rice. Moreover, the OsSSI2-kd plants showed markedly enhanced resistance to the blast fungus Magnaporthe grisea and leaf-blight bacteria Xanthomonas oryzae pv. oryzae. These results suggest that OsSSI2 is involved in the negative regulation of defense responses in rice, as are its Arabidopsis and soybean counterparts. Microarray analyses identified 406 genes that were differentially expressed (>or=2-fold) in OsSSI2-kd rice plants compared with wild-type rice and, of these, approximately 39% were BTH responsive. Taken together, our results suggest that induction of SA-responsive genes, including WRKY45, is likely responsible for enhanced disease resistance in OsSSI2-kd rice plants.

  18. Dietary fish oil supplements increase tissue n-3 fatty acid composition and expression of delta-6 desaturase and elongase-2 in Jade Tiger hybrid abalone.

    PubMed

    Mateos, Hintsa T; Lewandowski, Paul A; Su, Xiao Q

    2011-08-01

    This study was conducted to investigate the effects of fish oil (FO) supplements on fatty acid composition and the expression of ∆6 desaturase and elongase 2 genes in Jade Tiger abalone. Five test diets were formulated to contain 0.5, 1.0, 1.5, 2.0 and 2.5% of FO respectively, and the control diet was the normal commercial abalone diet with no additional FO supplement. The muscle, gonad and digestive glands (DG) of abalone fed with all of the five test diets showed significantly high levels of total n-3 polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), docosapentaenoic acid n-3 (DPAn-3), and docosahexaenoic acid (DHA) than the control group. In all three types of tissue, abalone fed diet supplemented with 1.5% FO showed the highest level of these fatty acids (P < 0.05). For DPAn-3 the higher level was also found in muscle and gonad of abalone fed diet supplemented with 2% FO (P < 0.05). Elongase 2 expression was markedly higher in the muscle of abalone fed diet supplemented with 1.5% FO (P < 0.05), followed by the diet containing 2% FO supplement. For ∆6 desaturase, significantly higher expression was observed in muscle of abalone fed with diet containing 0.5% FO supplement (P < 0.05). Supplementation with FO in the normal commercial diet can significantly improve long chain n-3 PUFA level in cultured abalone, with 1.5% being the most effective supplementation level.

  19. ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 Are Responsible for Making Omega-7 Fatty Acids in the Arabidopsis Aleurone1[OPEN

    PubMed Central

    Bryant, Fiona M.; Munoz-Azcarate, Olaya; Kurup, Smita; Eastmond, Peter J.

    2016-01-01

    Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3. We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ9 desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3. Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s. Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ9 desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids. PMID:27462083

  20. Desaturases from the spotted fireworm moth (Choristoneura parallela) shed light on the evolutionary origins of novel moth sex pheromone desaturases.

    PubMed

    Liu, Weitian; Rooney, Alejandro P; Xue, Bingye; Roelofs, Wendell L

    2004-11-24

    Six acyl-CoA desaturase-encoding cDNAs from mRNA isolated from the spotted fireworm moth, Choristoneura parallela (Lepidoptera: Tortricidae) were characterized and assayed for functionality. The expression levels of these cDNAs were determined in the pheromone gland and fat body by real-time PCR and the resulting patterns are in line with results from published studies on other moth sex pheromone desaturases. The cDNAs were found to correspond to six genes. Using both biochemical and phylogenetic analyses, four of these were found to belong to previously characterized desaturase functional groups [the Delta 10,11, the Delta 9 (16>18) and the Delta 9 (18>16) groups]. A desaturase highly expressed in the pheromone gland was a novel E11 desaturase that was specific to 14-carbon precursor acids. The fifth gene [CpaZ9(14-26)] was found to display a novel Z9 activity indicating that it belongs to a new Delta 9 functional group, whereas the sixth gene was determined to be nonfunctional with respect to desaturase activity. In accordance with previous studies, we find that desaturases of the Delta 10,11 and Delta 14 groups, which are the fastest evolving desaturases and possess the novel pheromone biosynthetic function, are expressed primarily in the pheromone gland whereas all other desaturases, which do not possess the novel reproductive function, evolve more slowly and display the ancestral metabolic function and pattern of gene expression.

  1. Long-term melatonin administration reduces hyperinsulinemia and improves the altered fatty-acid compositions in type 2 diabetic rats via the restoration of Delta-5 desaturase activity.

    PubMed

    Nishida, Shigeru; Segawa, Toshiko; Murai, Ichiro; Nakagawa, Shigeki

    2002-01-01

    The objective of this study was to investigate the effect of long-term melatonin administration on plasma levels of triglycerides, insulin and leptin, and on the fatty-acid metabolism of plasma and hepatic lipids in type 2 diabetic rats. Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of type 2 diabetes mellitus, were divided into two groups: one untreated (n=6), and one implanted with time-releasing melatonin pellets (1.1 mg/day for 30 wk) under the abdominal skin (n=6). Age-matched Long-Evans Tokushima Otsuka (LETO) rats (n=6) were used as healthy controls. The untreated diabetic rats had the increased plasma levels of triglycerides, cholesterol, insulin and leptin at 35 wk, as compared with the healthy control rats (n=6). The diabetic rats also had augmented ratios of 20:3n-6/20:4n-6 fatty acids, owing to diminished activity of Delta-5 desaturase, an insulin-permissive enzyme, in the liver. Melatonin administration to OLETF rats reduced the hypertriglyceridemia (-39%, P < 0.05), hyperinsulinemia (-33%, P < 0.01) and hyperleptinemia (-43%, P < 0.01), and restored hepatic Delta-5 desaturase activity (148%, P < 0.005). This resulted in a return to normal ratios of 20:3n-6/20:4n-6 fatty acids in plasma and hepatic lipids. There was a significant correlation (r=0.64, P < 0.005) between plasma levels of insulin and the ratios of 20:3n-6/20:4n-6 in plasma phospholipids of all rats in the three groups. Thus, subcutaneous implantation of a melatonin-releasing pellet thus resulted in improved lipid metabolism in diabetic rats, probably through restored insulin resistance.

  2. Metabolic engineering of omega-3 long-chain polyunsaturated fatty acids in plants using an acyl-CoA Delta6-desaturase with omega3-preference from the marine microalga Micromonas pusilla.

    PubMed

    Petrie, James R; Shrestha, Pushkar; Mansour, Maged P; Nichols, Peter D; Liu, Qing; Singh, Surinder P

    2010-05-01

    Long-chain (> or = C20) polyunsaturated fatty acids (LC-PUFA) EPA and DHA (20:5(Delta5,8,11,14,17) and 22:6(Delta4,7,10,13,16,19)) have well-documented health benefits against coronary heart disease, rheumatoid arthritis and other disorders. Currently, the predominant sources of these fatty acids are marine fish and algal oils, but research is being conducted to ensure that a sustainable, land-based production system can be developed. We here describe the metabolic engineering of an artificial pathway that produces 26% EPA in leaf triacylglycerol using a newly-identified Delta6-desaturase from the marine microalga Micromonas pusilla. We also demonstrate that this enzyme appears to function as an acyl-CoA desaturase that has preference for omega3 substrates both in planta and in yeast. Phylogenetic analysis indicates that this desaturase shares highly conserved motifs with previously described acyl-CoA Delta6-desaturases.

  3. Transgenic expression of n-3 fatty acid desaturase (fat-1) in C57/BL6 mice: Effects on glucose homeostasis and body weight.

    PubMed

    Ji, Shaonin; Hardy, Robert W; Wood, Philip A

    2009-07-01

    The fat-1 gene, derived from Caenorhabditis elegans, encodes for a fatty acid n-3 desaturase. In order to study the potential metabolic benefits of n-3 fatty acids, independent of dietary fatty acids, we developed seven lines of fat-1 transgenic mice (C57/BL6) controlled by the regulatory sequences of the adipocyte protein-2 (aP2) gene for adipocyte-specific expression (AP-lines). We were unable to obtain homozygous fat-1 transgenic offspring from the two highest expressing lines, suggesting that excessive expression of this enzyme may be lethal during gestation. Serum fatty acid analysis of fat-1 transgenic mice (AP-3) fed a high n-6 unsaturated fat (HUSF) diet had an n-6/n-3 fatty acid ratio reduced by 23% (P < 0.025) and the n-3 fatty acid eicosapentaenoic acid (EPA) concentration increased by 61% (P < 0.020). Docosahexaenoic acid (DHA) was increased by 19% (P < 0.015) in white adipose tissue. Male AP-3-fat-1 line of mice had improved glucose tolerance and reduced body weight with no change in insulin sensitivity when challenged with a high-carbohydrate (HC) diet. In contrast, the female AP-3 mice had reduced glucose tolerance and no change in insulin sensitivity or body weight. These findings indicate that male transgenic fat-1 mice have improved glucose tolerance likely due to increased insulin secretion while female fat-1 mice have reduced glucose tolerance compared to wild-type mice. Finally the inability of fat-1 transgenic mice to generate homozygous offspring suggests that prolonged exposure to increased concentrations of n-3 fatty acids may be detrimental to reproduction.

  4. Sequence variation determining stereochemistry of a Δ11 desaturase active in moth sex pheromone biosynthesis.

    PubMed

    Ding, Bao-Jian; Carraher, Colm; Löfstedt, Christer

    2016-07-01

    A Δ11 desaturase from the oblique banded leaf roller moth Choristoneura rosaceana takes the saturated myristic acid and produces a mixture of (E)-11-tetradecenoate and (Z)-11-tetradecenoate with an excess of the Z isomer (35:65). A desaturase from the spotted fireworm moth Choristoneura parallela also operates on myristic acid substrate but produces almost pure (E)-11-tetradecenoate. The two desaturases share 92% amino acid identity and 97% amino acid similarity. There are 24 amino acids differing between these two desaturases. We constructed mutations at all of these positions to pinpoint the sites that determine the product stereochemistry. We demonstrated with a yeast functional assay that one amino acid at the cytosolic carboxyl terminus of the protein (258E) is critical for the Z activity of the C. rosaceana desaturase. Mutating the glutamic acid (E) into aspartic acid (D) transforms the C. rosaceana enzyme into a desaturase with C. parallela-like activity, whereas the reciprocal mutation of the C. parallela desaturase transformed it into an enzyme producing an intermediate 64:36 E/Z product ratio. We discuss the causal link between this amino acid change and the stereochemical properties of the desaturase and the role of desaturase mutations in pheromone evolution.

  5. Survey of the total fatty acid and triacylglycerol composition and content of 30 duckweed species and cloning of a Δ6-desaturase responsible for the production of γ-linolenic and stearidonic acids in Lemna gibba

    PubMed Central

    2013-01-01

    Background Duckweeds, i.e., members of the Lemnoideae family, are amongst the smallest aquatic flowering plants. Their high growth rate, aquatic habit and suitability for bio-remediation make them strong candidates for biomass production. Duckweeds have been studied for their potential as feedstocks for bioethanol production; however, less is known about their ability to accumulate reduced carbon as fatty acids (FA) and oil. Results Total FA profiles of thirty duckweed species were analysed to assess the natural diversity within the Lemnoideae. Total FA content varied between 4.6% and 14.2% of dry weight whereas triacylglycerol (TAG) levels varied between 0.02% and 0.15% of dry weight. Three FA, 16:0 (palmitic), 18:2Δ9,12 (Linoleic acid, or LN) and 18:3Δ9,12,15 (α-linolenic acid, or ALA) comprise more than 80% of total duckweed FA. Seven Lemna and two Wolffiela species also accumulate polyunsaturated FA containing Δ6-double bonds, i.e., GLA and SDA. Relative to total FA, TAG is enriched in saturated FA and deficient in polyunsaturated FA, and only five Lemna species accumulate Δ6-FA in their TAG. A putative Δ6-desaturase designated LgDes, with homology to a family of front-end Δ6-FA and Δ8-spingolipid desaturases, was identified in the assembled DNA sequence of Lemna gibba. Expression of a synthetic LgDes gene in Nicotiana benthamiana resulted in the accumulation of GLA and SDA, confirming it specifies a Δ6-desaturase. Conclusions Total accumulation of FA varies three-fold across the 30 species of Lemnoideae surveyed. Nine species contain GLA and SDA which are synthesized by a Δ6 front-end desaturase, but FA composition is otherwise similar. TAG accumulates up to 0.15% of total dry weight, comparable to levels found in the leaves of terrestrial plants. Polyunsaturated FA is underrepresented in TAG, and the Δ6-FA GLA and SDA are found in the TAG of only five of the nine Lemna species that produce them. When present, GLA is enriched and SDA diminished

  6. Detection of quantitative trait loci affecting the milk fatty acid profile on sheep chromosome 22: role of the stearoyl-CoA desaturase gene in Spanish Churra sheep.

    PubMed

    García-Fernández, M; Gutiérrez-Gil, B; García-Gámez, E; Sánchez, J P; Arranz, J J

    2010-01-01

    Sheep milk fat contains several components that may provide human health benefits, such as monounsaturated fatty acids and conjugated linoleic acid (CLA). Most of the CLA in ruminant milk is synthesized in the mammary gland by the action of the enzyme stearoyl-CoA desaturase (SCD) on circulating vaccenic acid (trans-11 C18:2; VA). Previous studies have found significant associations between polymorphisms in the SCD gene and the fatty acid composition of ruminant products, including sheep milk. Based on this, we performed a quantitative trait loci (QTL) analysis of an ovine chromosome (22) that harbors the SCD gene for effects on milk fatty acid composition traits and classical milk production traits. We identified a suggestive QTL influencing the CLA/VA ratio with the maximum statistic at position 26 cM of the studied chromosome, whereas the SCD gene has been mapped to position 41.6 cM. The individual introduction of 4 SCD single nucleotide polymorphisms in the QTL model did not cause a reduction of the variance explained by the QTL, which suggests that the SCD gene is not directly responsible for the detected effect in the Churra population studied herein. This conclusion was supported by the lack of any significant association identified between the 4 SCD single nucleotide polymorphisms and the CLA/VA ratio. This association analysis suggested a possible effect of the SCD gene on milk fat percentage in Churra sheep. An independent confirmation of these primary results will be required before attempting its practical implementation in selection programs.

  7. Subcutaneous and intramuscular adipose tissue stearoyl-coenzyme A desaturase gene expression and fatty acid composition in calf- and yearling-fed Angus steers.

    PubMed

    Brooks, M A; Choi, C W; Lunt, D K; Kawachi, H; Smith, S B

    2011-08-01

    We proposed that stearoyl-CoA desaturase (SCD) activity dictates fatty acid composition of adipose tissue and muscle in beef cattle, regardless of ruminal or hepatic fatty acid hydrogenation or desaturation. Twelve Angus steers were assigned to a calf-fed (CF) group and slaughtered at weaning (8 mo of age; n=4), 12 mo of age (n=4), or 16 mo of age (n=4). Twelve steers were assigned to a yearling-fed (YF) group and slaughtered at 12 mo of age (n=4), 16 mo of age (n=4), and 17.5 mo of age (n=4; 525 kg, market weight). Data were analyzed based on time on the corn-based finishing diet, with terminal age as a covariate, and orthogonal polynomial contrasts were tested on the main effects of treatment group and time on the finishing diet. Fatty acids from duodenal digesta, plasma, liver, LM, and subcutaneous and intramuscular adipose tissue were measured, and SCD gene expression was measured in intramuscular and subcutaneous adipose tissues. In duodenal digesta, palmitic and linoleic acids increased by 100% over the sampling period, α-linolenic acid decreased over the sampling period, and trans-vaccenic acid was greater in YF than in CF steers (all P < 0.01). The proportion of α-linolenic acid decreased over time in all tissues, including liver. The SCD index (ratio of SCD fatty acid products to SCD fatty acid substrates) increased over time in LM and in intramuscular and subcutaneous adipose tissues. The SCD:glyceraldehyde 3-phosphate dehydrogenase mRNA ratio was virtually undetectable at the initial sampling periods in subcutaneous adipose tissue of YF and CF steers, and it increased over time (P < 0.01). The SCD index and SCD:glyceraldehyde 3-phosphate dehydrogenase ratio were greater in intramuscular adipose tissue of CF steers than in that of YF steers. The SCD index did not change over time in liver and decreased over time in duodenal digesta. We conclude that, unlike essential fatty acids, the SFA and MUFA composition of adipose tissue is regulated by adipose

  8. Enrichment of maternal diet with conjugated linoleic acids influences desaturases activity and fatty acids profile in livers and hepatic microsomes of the offspring with 7,12-dimethylbenz[a]anthracene-induced mammary tumors.

    PubMed

    Białek, Agnieszka; Stawarska, Agnieszka; Tokarz, Andrzej; Czuba, Katarzyna; Konarska, Anna; Mazurkiewicz, Magdalena

    2014-01-01

    The aim of this study was to assess the influence of diet supplementation of pregnant and breast-feeding female Sprague-Dawley rats with conjugated linoleic acids (CLA) on the Δ6- and Δ5-desaturase activity in hepatic microsomes as well as on fatty acids profile and lipids peroxidation in liver and hepatic microsomes of the progeny with chemically induced mammary tumors. Rats were divided into two groups with different diet supplementation (vegetable oil (which did not contain CLA) or CLA). Their female offspring was divided within these groups into two subgroups: (1)--fed the same diet as mothers (K1 - oil, 01 - CLA), and (2)--fed the standard fodder (K2, O2). At 50th day of life, the progeny obtained carcinogenic agent (7,12-dimethylbenz[a]anthracene). Higher supply of CLA in diet of mothers resulted in lower susceptibility to chemically induced mammary tumors in their offspring (p = 0.0322). It also influenced the fatty acids profile in livers and in hepatic microsomes, especially polyunsaturated n3 and n6 fatty acids. CLA inhibited the activity of the desaturases, which confirmed that CLA can reduce the level of arachidonic acid directly, reducing linoleic acid content in membranes, or indirectly, through the regulation of its metabolism. We were unable to confirm or deny the antioxidative properties of CLA. Our results indicate that the higher supply of CLA in mothers' diet during pregnancy and breastfeeding causes their incorporation into tissues of children, changes the efficiency of fatty acids metabolism and exerts health-promoting effect in their adult life reducing the breast cancer risk.

  9. The stearoyl-coenzyme A desaturase 1 is essential for virulence and membrane stress in Candida parapsilosis through unsaturated fatty acid production.

    PubMed

    Nguyen, Long Nam; Gacser, Attila; Nosanchuk, Joshua D

    2011-01-01

    Unsaturated fatty acids (UFA) are essential components of cells. In Saccharomyces cerevisiae, stearoyl-coenzyme A (CoA) desaturase 1 (OLE1) affects cell viability through the regulation of oleic (18:1) or palmitoleic (16:1) acid production. In this study, we used a targeted gene deletion approach to determine the impact of OLE1 on the emerging human pathogenic fungus Candida parapsilosis. We found that the deletion of OLE1 resulted in an auxotrophic yeast strain (designated OLE1 KO) that required unsaturated fatty acids for growth but not saturated fatty acids. Additionally, the production of UFA by OLE1 KO yeast cells was markedly reduced, suggesting that Ole1 is essential for UFA production. In contrast to wild-type C. parapsilosis, which produced pseudohyphal growth on UFA-supplemented medium agar, pseudohyphal formation in the OLE1 KO cells was severely impaired, suggesting that Ole1 regulates morphology. Furthermore, the OLE1 KO cells were hypersensitive to various stress-inducing factors, such as salts, SDS, and H(2)O(2), especially at the physiological temperature. The results indicate that OLE1 is essential for the stress response, perhaps through the production of UFA for cell membrane biosynthesis. The OLE1 KO cells also were hypersensitive to human and fetal bovine serum, suggesting that targeting Ole1 could suppress the dissemination of yeast cells in the bloodstream. Murine-like macrophage J774.16 more efficiently killed the OLE1 KO yeasts, and significantly larger amounts of nitric oxide were detected in cocultures of macrophages and OLE1 KO cells than with wild-type or heterozygous strains. Moreover, the disruption of OLE1 significantly reduced fungal virulence in systemic murine infection. Taken together, these results demonstrate that Ole1 regulates the pathobiology of C. parapsilosis via UFA and that the OLE1 pathway is a promising antifungal target.

  10. Carrot Juice Administration Decreases Liver Stearoyl-CoA Desaturase 1 and Improves Docosahexaenoic Acid Levels, but Not Steatosis in High Fructose Diet-Fed Weanling Wistar Rats

    PubMed Central

    Mahesh, Malleswarapu; Bharathi, Munugala; Reddy, Mooli Raja Gopal; Kumar, Manchiryala Sravan; Putcha, Uday Kumar; Vajreswari, Ayyalasomayajula; Jeyakumar, Shanmugam M.

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases associated with an altered lifestyle, besides genetic factors. The control and management of NAFLD mostly depend on lifestyle modifications, due to the lack of a specific therapeutic approach. In this context, we assessed the effect of carrot juice on the development of high fructose-induced hepatic steatosis. For this purpose, male weanling Wistar rats were divided into 4 groups, fed either a control (Con) or high fructose (HFr) diet of AIN93G composition, with or without carrot juice (CJ) for 8 weeks. At the end of the experimental period, plasma biochemical markers, such as triglycerides, alanine aminotransferase, and β-hydroxy butyrate levels were comparable among the 4 groups. Although, the liver injury marker, aspartate aminotransferase, levels in plasma showed a reduction, hepatic triglycerides levels were not significantly reduced by carrot juice ingestion in the HFr diet-fed rats (HFr-CJ). On the other hand, the key triglyceride synthesis pathway enzyme, hepatic stearoyl-CoA desaturase 1 (SCD1), expression at mRNA level was augmented by carrot juice ingestion, while their protein levels showed a significant reduction, which corroborated with decreased monounsaturated fatty acids (MUFA), particularly palmitoleic (C16:1) and oleic (C18:1) acids. Notably, it also improved the long chain n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA; C22:6) content of the liver in HFr-CJ. In conclusion, carrot juice ingestion decreased the SCD1-mediated production of MUFA and improved DHA levels in liver, under high fructose diet-fed conditions. However, these changes did not significantly lower the hepatic triglyceride levels. PMID:27752492

  11. Genome-wide identification of membrane-bound fatty acid desaturase genes in Gossypium hirsutum and their expressions during abiotic stress

    PubMed Central

    Feng, Jiyu; Dong, Yating; Liu, Wei; He, Qiuling; Daud, M. K.; Chen, Jinhong; Zhu, Shuijin

    2017-01-01

    Membrane-bound fatty acid desaturases (FADs) are of great importance and play multiple roles in plant growth and development. In the present study, 39 full-length FAD genes, based on database searches, were identified in tetraploid upland cotton (Gossypium hirsutum L.) and were phylogenetically clustered into four subfamilies. Genomic localization revealed that 34 genes were mapped on 22 chromosomes, and five genes were positioned on the scaffold sequences. The FAD genes of G. hirsutum in the same subfamily had similar gene structures. The structures of paralogous genes were considerably conserved in exons number and introns length. It was suggested that the FAD gene families in G. hirsutum might be duplicated mainly by segmental duplication. Moreover, the FAD genes were differentially expressed in different G. hirsutum tissues in response to different levels of salt and cold stresses, as determined by qRT-PCR analysis. The identification and functional analysis of FAD genes in G. hirsutum may provide more candidate genes for genetic modification. PMID:28374822

  12. Membrane-bound fatty acid desaturases are inserted co-translationally into the ER and contain different ER retrieval motifs at their carboxy termini.

    PubMed

    McCartney, Andrew W; Dyer, John M; Dhanoa, Preetinder K; Kim, Peter K; Andrews, David W; McNew, James A; Mullen, Robert T

    2004-01-01

    Fatty acid desaturases (FADs) play a prominent role in plant lipid metabolism and are located in various subcellular compartments, including the endoplasmic reticulum (ER). To investigate the biogenesis of ER-localized membrane-bound FADs, we characterized the mechanisms responsible for insertion of Arabidopsis FAD2 and Brassica FAD3 into ER membranes and determined the molecular signals that maintain their ER residency. Using in vitro transcription/translation reactions with ER-derived microsomes, we show that both FAD2 and FAD3 are efficiently integrated into membranes by a co-translational, translocon-mediated pathway. We also demonstrate that while the C-terminus of FAD3 (-KSKIN) contains a functional prototypic dilysine ER retrieval motif, FAD2 contains a novel C-terminal aromatic amino acid-containing sequence (-YNNKL) that is both necessary and sufficient for maintaining localization in the ER. Co-expression of a membrane-bound reporter protein containing the FAD2 C-terminus with a dominant-negative mutant of ADP-ribosylation factor (Arf)1 abolished transient localization of the reporter protein in the Golgi, indicating that the FAD2 peptide signal acts as an ER retrieval motif. Mutational analysis of the FAD2 ER retrieval signal revealed a sequence-specific motif consisting of Phi-X-X-K/R/D/E-Phi-COOH, where -Phi- are large hydrophobic amino acid residues. Interestingly, this aromatic motif was present in a variety of other known and putative ER membrane proteins, including cytochrome P450 and the peroxisomal biogenesis factor Pex10p. Taken together, these data describe the insertion and retrieval mechanisms of FADs and define a new ER localization signal in plants that is responsible for the retrieval of escaped membrane proteins back to the ER.

  13. Production of 5,8,11-Eicosatrienoic Acid (Mead Acid) by a (Delta)6 Desaturation Activity-Enhanced Mutant Derived from a (Delta)12 Desaturase-Defective Mutant of an Arachidonic Acid-Producing Fungus, Mortierella alpina 1S-4.

    PubMed

    Kawashima, H; Nishihara, M; Hirano, Y; Kamada, N; Akimoto, K; Konishi, K; Shimizu, S

    1997-05-01

    Enhanced production of 5,8,11-eicosatrienoic acid (Mead acid, 20:3(omega)9) was attained by a mutant fungus, Mortierella alpina M209-7, derived from (Delta)12 desaturase-defective M. alpina Mut48. The 20:3(omega)9 production by M209-7 was 1.3 times greater than that by its parent strain, Mut48. This is thought to be due to its enhanced (Delta)6 desaturation activity, which was 1.4 times higher than that of Mut48. In both strains, 87 to 88% of the total lipids comprised triacylglycerol (TG) and 85% of 20:3(omega)9 was contained in TG. On optimization of the culture conditions for M209-7, earlier glucose feeding and shifting of the growth temperature from 28 to 19(deg)C on the second day were shown to be effective. Under the optimal conditions with a 10-liter jar fermentor, 20:3(omega)9 production reached 1.65 g/liter of culture medium (corresponding to 118 mg/g of dry mycelia and 28.9% of total fatty acids), which is about twice that reported previously (0.8 g/liter).

  14. Identification of a Δ5-like fatty acyl desaturase from the cephalopod Octopus vulgaris (Cuvier 1797) involved in the biosynthesis of essential fatty acids.

    PubMed

    Monroig, Oscar; Navarro, Juan C; Dick, James R; Alemany, Frederic; Tocher, Douglas R

    2012-08-01

    Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due, in part, to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval stages of the common octopus through characterisation of the enzymes of endogenous LC-PUFA biosynthetic pathways. In this study, we isolated a cDNA with high homology to fatty acyl desaturases (Fad). Functional characterisation in recombinant yeast showed that the octopus Fad exhibited Δ5-desaturation activity towards saturated and polyunsaturated fatty acyl substrates. Thus, it efficiently converted the yeast's endogenous 16:0 and 18:0 to 16:1n-11 and 18:1n-13, respectively, and desaturated exogenously added PUFA substrates 20:4n-3 and 20:3n-6 to 20:5n-3 (EPA) and 20:4n-6 (ARA), respectively. Although the Δ5 Fad enables common octopus to produce EPA and ARA, the low availability of its adequate substrates 20:4n-3 and 20:3n-6, either in the diet or by limited endogenous synthesis from C(18) PUFA, might indicate that EPA and ARA are indeed EFA for this species. Interestingly, the octopus Δ5 Fad can also participate in the biosynthesis of non-methylene-interrupted FA, PUFA that are generally uncommon in vertebrates but have been found previously in marine invertebrates, including molluscs, and now also confirmed to be present in specific tissues of common octopus.

  15. Functional analysis of the omega-6 fatty acid desaturase (CaFAD2) gene family of the oil seed crop Crambe abyssinica

    PubMed Central

    2013-01-01

    Background Crambe abyssinica produces high erucic acid (C22:1, 55-60%) in the seed oil, which can be further increased by reduction of polyunsaturated fatty acid (PUFA) levels. The omega-6 fatty acid desaturase enzyme (FAD2) is known to be involved in PUFA biosynthesis. In crambe, three CaFAD2 genes, CaFAD2-C1, CaFAD2-C2 and CaFAD2-C3 are expressed. Results The individual effect of each CaFAD2 gene on oil composition was investigated through studying transgenic lines (CaFAD2-RNAi) for differential expression levels in relation to the composition of seed-oil. Six first generation transgenic plants (T1) showed C18:1 increase (by 6% to 10.5%) and PUFA reduction (by 8.6% to 10.2%). The silencing effect in these T1-plants ranged from the moderate silencing (40% to 50% reduction) of all three CaFAD2 genes to strong silencing (95% reduction) of CaFAD2-C3 alone. The progeny of two T1-plants (WG4-4 and WG19-6) was further analysed. Four or five transgene insertions are characterized in the progeny (T2) of WG19-6 in contrast to a single insertion in the T2 progeny of WG4-4. For the individual T2-plants of both families (WG19-6 and WG4-4), seed-specific silencing of CaFAD2-C1 and CaFAD2-C2 was observed in several individual T2-plants but, on average in both families, the level of silencing of these genes was not significant. A significant reduction in expression level (P < 0.01) in both families was only observed for CaFAD2-C3 together with significantly different C18:1 and PUFA levels in oil. Conclusions CaFAD2-C3 expression is highly correlated to levels of C18:1 (r = -0.78) and PUFA (r = 0.75), which suggests that CaFAD2-C3 is the most important one for changing the oil composition of crambe. PMID:24083776

  16. An insect with a delta-12 desaturase, the jewel wasp Nasonia vitripennis, benefits from nutritional supply with linoleic acid

    NASA Astrophysics Data System (ADS)

    Brandstetter, Birgit; Ruther, Joachim

    2016-06-01

    The availability of linoleic acid (LA; C18:2∆9,12) is pivotal for animals. While vertebrates depend on a nutritional supply, some invertebrates, including the parasitic wasp Nasonia vitripennis, are able to synthesize LA from oleic acid (OA; C18:1∆9). This raises the question as to whether these animals nevertheless benefit from the additional uptake of LA with the diet. LA plays an important role in the sexual communication of N. vitripennis because males use it as a precursor for the synthesis of an abdominal sex pheromone attracting virgin females. We reared hosts of N. vitripennis that were fed diets enriched in the availability of stearic acid (SA: C18:0), OA or LA. N. vitripennis males developing on the different host types clearly differed in both the fatty acid composition of their body fat and sex pheromone titres. Males from LA-enriched hosts had an almost fourfold higher proportion of LA and produced significantly more sex pheromone than males from SA (2.2-fold) and OA (1.4-fold) enriched hosts, respectively. Our study demonstrates that animals being able to synthesize important nutrients de novo may still benefit from an additional supply with their diet.

  17. Characterization of the promoter and 5'-UTR intron of oleic acid desaturase (FAD2) gene in Brassica napus.

    PubMed

    Xiao, Gang; Zhang, Zhen Qian; Yin, Chang Fa; Liu, Rui Yang; Wu, Xian Meng; Tan, Tai Long; Chen, She Yuan; Lu, Chang Ming; Guan, Chun Yun

    2014-07-15

    In the present study, we characterized the transcriptional regulatory region (KF038144) controlling the expression of a constitutive FAD2 in Brassica napus. There are multiple FAD2 gene copies in B. napus genome. The FAD2 gene characterized and analyzed in the study is located on chromosome A5 and was designated as BnFAD2A5-1. BnFAD2A5-1 harbors an intron (1,192 bp) within its 5'-untranslated region (5'-UTR). This intron demonstrated promoter activity. Deletion analysis of the BnFAD2A5-1 promoter and intron through the β-glucuronidase (GUS) reporter system revealed that the -220 to -1 bp is the minimum promoter region, while -220 to -110 bp and +34 to +285 bp are two important regions conferring high-levels of transcription. BnFAD2 transcripts were induced by light, low temperature, and abscisic acid (ABA). These observations demonstrated that not only the promoter but also the intron are involved in controlling the expression of the BnFAD2A5-1 gene. The intron-mediated regulation is an essential aspect of the gene expression regulation.

  18. Oral administration of cobalt acetate alters milk fatty acid composition, consistent with an inhibition of stearoyl-coenzyme A desaturase in lactating ewes.

    PubMed

    Frutos, P; Toral, P G; Ramos-Morales, E; Shingfield, K J; Belenguer, A; Hervás, G

    2014-02-01

    Previous investigations have shown that cobalt (Co) modifies milk fat composition in cattle, consistent with an inhibition of stearoyl-coenzyme A desaturase (SCD) activity, but it remains unclear whether other ruminant species are also affected. The present study examined the effects of oral administration of Co acetate on intake, rumen function, and milk production and fatty acid (FA) composition in sheep. Twenty lactating Assaf ewes were allocated into 1 of 4 groups and used in a continuous randomized block design that involved a 15-d adaptation, a 6-d treatment, and a 10-d posttreatment period. During the treatment period, animals received an oral drench supplying 0 (control), 3 (Co3), 6 (Co6), and 9 (Co9) mg of Co/kg of BW per day, administered in 3 equal doses at 8-h intervals. Cobalt acetate had no influence on intake or milk fat and protein concentrations, whereas treatments Co6 and Co9 tended to lower milk yield. Results on rumen parameters showed no effects on rumen fermentation, FA composition, or bacterial community structure. Administration of Co acetate decreased milk concentrations of FA containing a cis-9 double bond and SCD product:substrate ratios, consistent with an inhibition of SCD activity in the ovine mammary gland. Temporal changes in milk fat composition indicated that the effects of treatments were evident within 3d of dosing, with further changes being apparent after 6d and reverting to pretreatment values by d 6 after administration. Effect on milk FA composition did not differ substantially in response to incremental doses of Co acetate. On average, Co decreased milk cis-9 10:1/10:0, cis-9 12:1/12:0, cis-9 14:1/14:0, cis-9 16:1/16:0, cis-9 17:1/17:0, cis-9 18:1/18:0, and cis-9,trans-11 18:2/trans-11 18:1 concentration ratios by 30, 32, 38, 33, 21, 24, and 25%, respectively. Changes in milk fat cis-9 10:1, cis-9 12:1, and cis-9 14:1 concentrations to Co treatment indicated that 51% of cis-9 18:1 and cis-9,trans-11 18:2 secreted in milk

  19. Δ6-fatty acid desaturase and fatty acid elongase mRNA expression, phagocytic activity and weight-to-length relationships in channel catfish (Ictalurus punctatus) fed alternative diets with soy oil and a probiotic.

    PubMed

    Santerre, A; Téllez-Bañuelos, M C; Casas-Solís, J; Castro-Félix, P; Huízar-López, M R; Zaitseva, G P; Horta-Fernández, J L; Trujillo-García, E A; de la Mora-Sherer, D; Palafox-Luna, J A; Juárez-Carrillo, E

    2015-09-22

    A time-course feeding trial was conducted for 120 days on juvenile channel catfish (Ictalurus punctatus) to study the effects of diets differing in oil source (fish oil or soy oil) and supplementation with a commercial probiotic. Relative levels of Δ6-fatty acid desaturase (Δ6-FAD) and fatty acid elongase (FAE) expression were assessed in brain and liver tissues. Both genes showed similar expression levels in all groups studied. Fish weight-to-length relationships were evaluated using polynomial regression analyses, which identified a burst in weight and length in the channel catfish on day 105 of treatment; this increase was related to an increase in gene expression. Mid-intestinal lactic acid bacterium (LAB) count was determined according to morphological and biochemical criteria using API strips. There was no indication that intestinal LAB count was affected by the modified diets. The Cunningham glass adherence method was applied to evaluate phagocytic cell activity in peripheral blood. Reactive oxygen species (ROS) generation was assessed through the respiratory burst activity of spleen macrophages by the NBT reduction test. Probiotic-supplemented diets provided a good substrate for innate immune system function; the phagocytic index was significantly enhanced in fish fed soy oil and the probiotic, and at the end of the experimental period, ROS production increased in fish fed soy oil. The substitution of fish oil by soy oil is recommended for food formulation and will contribute to promoting sustainable aquaculture. Probiotics are also recommended for channel catfish farming as they may act as immunonutrients.

  20. Identification of functional BrFAD2-1 gene encoding microsomal delta-12 fatty acid desaturase from Brassica rapa and development of Brassica napus containing high oleic acid contents.

    PubMed

    Jung, Jin Hee; Kim, Hyojin; Go, Young Sam; Lee, Saet Buyl; Hur, Cheol-Goo; Kim, Hyun Uk; Suh, Mi Chung

    2011-10-01

    Microsomal delta-12 fatty acid desaturase (FAD2) functions in the first committed step of the biosynthesis of polyunsaturated fatty acids via the desaturation of oleic acid to linoleic acid. In this study, two FAD2 genes were identified through genome-wide analysis of Brassica rapa. One BrFAD2-1 gene harbors functional sequence information, but another BrFAD2-2 gene has mutations that generated a premature stop codon, rendering it nonfunctional. From a database of 120,000 B. rapa expressed sequence tags, we determined that all sequences coding for FAD2 corresponded to the BrFAD2-1 gene. The BrFAD2-1 protein was shown to share high sequence homology (71-99%) with FAD2 proteins from other plant species. An intron in the 5'-untranslated region and three histidine boxes in the protein, which are characteristic of plant FAD2 genes, have been well-conserved. BrFAD2-1 transcripts were detected in various organs of B. rapa. When a pBrFAD2-1:mRFP construct was introduced into tobacco epidermal cells, the fluorescent signal was noted in the endoplasmic reticulum. Ectopic expression of BrFAD2-1:mRFP complemented the Arabidopsis fad2-2 mutant. Finally, transgenic Korean rapeseed Tammi containing high oleic acid contents (78 mol%) was developed via the expression of the BrFAD2-1 gene in an antisense orientation. The data demonstrate that B. rapa harbors only one functional FAD2 that can be utilized for the development of the high-oleic acid Korean rapeseed cultivar Tammi, which might be useful for both human consumption and industrial applications.

  1. Effects of bovine fatty acid synthase, stearoyl-coenzyme A desaturase, sterol regulatory element-binding protein 1, and growth hormone gene polymorphisms on fatty acid composition and carcass traits in Japanese Black cattle.

    PubMed

    Matsuhashi, T; Maruyama, S; Uemoto, Y; Kobayashi, N; Mannen, H; Abe, T; Sakaguchi, S; Kobayashi, E

    2011-01-01

    The quality of fat is an important factor in defining the quality of meat. Fat quality is determined by the composition of fatty acids. Among lipid metabolism-related genes, including fatty acid synthesis genes, several genetic variations have been reported in the bovine fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), sterol regulatory element-binding protein 1 (SREBP1), and GH genes. In the present study, we evaluated the single and epistatic effects of 5 genetic variations (4 SNP and 1 insertion/deletion) in 4 genes (FASN, SCD, SREBP1, and GH) on the fatty acid composition of the longissimus thoracis muscle and carcass and meat quality traits in 480 commercial Japanese Black cattle. Significant single effects of FASN, SCD, and GH(L127V) polymorphisms on the fatty acid composition of the longissimus thoracis muscle were detected. The A293V polymorphism of SCD had the largest effect on myristic acid (C14:0, P < 0.001), myristoleic acid (C14:1, P < 0.001), stearic acid (C18:0, P < 0.001), oleic acid (C18:1, P < 0.001), and MUFA (P < 0.001). Polymorphisms in the FASN, SCD, and SREBP1 genes showed no effect on any meat yield trait. There were no significant epistatic effects on fatty acid composition among pairs of the 3 genes (FASN, SCD, and SREBP1) involved in fatty acid synthesis. No epistatic interactions (P > 0.1) were detected between FASN and SCD for any carcass trait. When the genotypes of 3 markers (FASN, SCD, and GH(L127V)) were substituted from the lesser effect allele to the greater effect allele, the proportion of C18:1 increased by 4.46%. More than 20% of the genetic variance in the C18:1 level could be accounted for by these 3 genetic markers. The present results revealed that polymorphisms in 2 fatty acid synthesis genes (FASN and SCD) independently influenced fatty acid composition in the longissimus thoracis muscle. These results suggest that SNP in the FASN and SCD genes are useful markers for the improvement of fatty acid composition in

  2. Contribution of omega-3 fatty acid desaturase and 3-ketoacyl-ACP synthase II (KASII) genes in the modulation of glycerolipid fatty acid composition during cold acclimation in birch leaves.

    PubMed

    Martz, Françoise; Kiviniemi, Sari; Palva, Tapio E; Sutinen, Marja-Liisa

    2006-01-01

    Temperate and boreal tree species respond to low positive temperatures (LT) or a shortening of the photoperiod (SD) by inducing cold acclimation. One of the metabolic consequences of cold acclimation is an increase in fatty acid (FA) desaturation in membrane lipids, which allows functional membrane fluidity to be maintained at LT. The molecular mechanisms of FA desaturation were investigated in leaves of birch seedlings (Betula pendula) during cold acclimation. Four genes involved in FA biosynthesis were isolated: a 3-ketoacyl-ACP synthase II gene (BpKASII) involved in the elongation of palmitoyl-ACP to stearoyl-ACP, and three omega-3 FA desaturase genes (BpFAD3, BpFAD7, and BpFAD8) involved in the desaturation of linoleic acid (18:2) to alpha-linolenic acid (18:3). BpFAD7 was the main omega-3 FAD gene expressed in birch leaves, and it was down-regulated by LT under SD conditions. LT induced the expression of BpFAD3 and BpFAD8 and a synchronous increase in 18:3 occurred in glycerolipids. Changes in the photoperiod did not affect the LT-induced increase in 18:3 in chloroplast lipids (MGDG, DGDG, PG), but it modulated the LT response detected in extra-chloroplastic lipids (PC, PE, PI, PS). A decrease in the proportion of the 16-carbon FAs in lipids occurred at LT, possibly in relation to the regulation of BpKASII expression at LT. These results suggest that LT affects the whole FA biosynthesis pathway. They support a co-ordinated action of microsomal (BpFAD3) and chloroplast enzymes (BpFAD7, BpFAD8) in determining the level of 18:3 in extra-chloroplastic membranes, and they highlight the importance of dynamic lipid trafficking.

  3. Oleic acid synthesized by stearoyl-CoA desaturase (SCD-1) in the lateral periventricular zone of the developing rat brain mediates neuronal growth, migration and the arrangement of prospective synapses.

    PubMed

    Polo-Hernández, Erica; Tello, Vega; Arroyo, Angel A; Domínguez-Prieto, Marta; de Castro, Fernando; Tabernero, Arantxa; Medina, José M

    2014-06-27

    Our previous work has shown that oleic acid synthesized by astrocytes in response to serum albumin behaves as a neurotrophic factor in neurons, upregulating the expression of GAP-43 and MAP-2 proteins, which are respectively markers of axonal and dendrite growth. In addition, oleic acid promoted neuron migration and aggregation, resulting in clusters of neurons connected each other by the newly formed neurites. In this work we show that the presence of albumin or albumin plus oleic acid increases neuron migration in cultured explants of the lateral periventricular zone, resulting in an increase in the number of GAP-43-positive neurons leaving the explant. Upon silencing stearoyl-CoA desaturase-1 (SCD-1), a key enzyme in oleic acid synthesis by RNA of interference mostly prevented the effect of albumin but not that of albumin plus oleic acid, suggesting that the oleic acid synthesized due to the effect of albumin would be responsible for the increase in neuron migration. Oleic acid increased doublecortin (DCX) expression in cultured neurons, explants and organotypic slices, suggesting that DCX may mediate in the effect of oleic acid on neuron migration. The effect of oleic acid on neuron migration may be destined for the formation of synapses because the presence of oleic acid increased the expression of synaptotagmin and that of postsynaptic density protein (PDS-95), respectively markers of the pre- and postsynaptic compartments. In addition, confocal microscopy revealed the occurrence of points of colocalization between synaptotagmin and PDS-95, which is consistent with the idea that oleic acid promotes synapse arrangement.

  4. Lipid redistribution by α-linolenic acid-rich chia seed inhibits stearoyl-CoA desaturase-1 and induces cardiac and hepatic protection in diet-induced obese rats.

    PubMed

    Poudyal, Hemant; Panchal, Sunil K; Waanders, Jennifer; Ward, Leigh; Brown, Lindsay

    2012-02-01

    Chia seeds contain the essential fatty acid, α-linolenic acid (ALA). This study has assessed whether chia seeds attenuated the metabolic, cardiovascular and hepatic signs of a high-carbohydrate, high-fat (H) diet [carbohydrates, 52% (wt/wt); fat, 24% (wt/wt) with 25% (wt/vol) fructose in drinking water] in rats. Diets of the treatment groups were supplemented with 5% chia seeds after 8 weeks on H diet for a further 8 weeks. Compared with the H rats, chia seed-supplemented rats had improved insulin sensitivity and glucose tolerance, reduced visceral adiposity, decreased hepatic steatosis and reduced cardiac and hepatic inflammation and fibrosis without changes in plasma lipids or blood pressure. Chia seeds induced lipid redistribution with lipid trafficking away from the visceral fat and liver with an increased accumulation in the heart. The stearoyl-CoA desaturase-1 products were depleted in the heart, liver and the adipose tissue of chia seed-supplemented rats together with an increase in the substrate concentrations. The C18:1trans-7 was preferentially stored in the adipose tissue; the relatively inert C18:1n-9 was stored in sensitive organs such as liver and heart and C18:2n-6, the parent fatty acid of the n-6 pathway, was preferentially metabolized. Thus, chia seeds as a source of ALA induce lipid redistribution associated with cardioprotection and hepatoprotection.

  5. The delta 6 desaturase knock out mouse reveals that immunomodulatory effects of essential n-6 and n-3 polyunsaturated fatty acids are both independent of and dependent upon conversion.

    PubMed

    Monk, Jennifer M; Liddle, Danyelle M; Cohen, Daniel J A; Tsang, Denis H; Hillyer, Lyn M; Abdelmagid, Salma A; Nakamura, Manabu T; Power, Krista A; Ma, David W L; Robinson, Lindsay E

    2016-06-01

    Typically fatty acids (FA) exert differential immunomodulatory effects with n-3 [α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and n-6 [linoleic acid (LA) and arachidonic acid (AA)] exerting anti- and pro-inflammatory effects, respectively. This over-simplified interpretation is confounded by a failure to account for conversion of the parent FA (LA and ALA) to longer-chain bioactive products (AA and EPA/DHA, respectively), thereby precluding discernment of the immunomodulatory potential of specific FA. Therefore, we utilized the Δ6-desaturase model, wherein knockout mice (D6KO) lack the Fads2 gene encoding for the rate-limiting enzyme that initiates FA metabolism, thereby providing a model to determine specific FA immunomodulatory effects. Wild-type (WT) and D6KO mice were fed one of four isocaloric diets differing in FA source (9weeks): corn oil (LA-enriched), arachidonic acid single cell oil (AA-enriched), flaxseed oil (ALA-enriched) or menhaden fish oil (EPA/DHA-enriched). Splenic mononuclear cell cytokine production in response to lipopolysaccharide (LPS), T-cell receptor (TCR) and anti-CD40 stimulation was determined. Following LPS stimulation, AA was more bioactive compared to LA, by increasing inflammatory cytokine production of IL-6 (1.2-fold) and TNFα (1.3-fold). Further, LPS-stimulated IFNγ production in LA-fed D6KO mice was reduced 5-fold compared to LA-fed WT mice, indicating that conversion of LA to AA was necessary for cytokine production. Conversely, ALA exerted an independent immunomodulatory effect from EPA/DHA and all n-3 FA increased LPS-stimulated IL-10 production versus LA and AA. These data definitively identify specific immunomodulatory effects of individual FA and challenge the simplified view of the immunomodulatory effects of n-3 and n-6 FA.

  6. Corn oil supplementation to steers grazing endophyte-free tall fescue. II. Effects on longissimus muscle and subcutaneous adipose fatty acid composition and stearoyl-CoA desaturase activity and expression.

    PubMed

    Pavan, E; Duckett, S K

    2007-07-01

    Eighteen steers were used to evaluate the effect of supplemental corn oil level to steers grazing endophyte-free tall fescue on fatty acid composition of LM, stearoyl CoA desaturase (SCD) activity and expression as well as cellularity in s.c. adipose. Corn oil was supplemented (g/kg of BW) at 0 (none), 0.75 (medium), and 1.5 (high). Cottonseed hulls were used as a carrier for the corn oil and were supplemented according to pasture availability (0.7 to 1% of BW). Steers were finished on a rotationally grazed, tall fescue pasture for 116 d. Fatty acid composition of LM, s.c. adipose, and diet was determined by GLC. Total linoleic acid intake increased linearly (P < 0.01) with corn oil supplementation (90.7, 265.1, and 406.7 g in none, medium, and high, respectively). Oil supplementation linearly reduced (P < 0.05) myristic, palmitic, and linolenic acid percentage in LM and s.c. adipose. Vaccenic acid (C18:1 t11; VA) percentage was 46 and 32% greater (linear, P = 0.02; quadratic, P = 0.01) for medium and high, respectively, than none, regardless of tissue. Effect of oil supplementation on CLA cis-9, trans-11 was affected by type of adipose tissue (P < 0.01). In the LM, CLA cis-9, trans-11 isomer was 25% greater for medium than for none and intermediate for high, whereas CLA cis-9, trans-11 CLA isomer was 48 and 33% greater in s.c. adipose tissue for medium and high than for none, respectively. Corn oil linearly increased (P acid and CLA trans-10, cis-12; however, values were low (<0.35 and <0.035% of total fatty acids, respectively). Oil supplementation did not change (P > 0.05) the percentage of total SFA, MUFA, or PUFA but linearly increased (P = 0.03) n-6:n-3 ratio from 2.4 to 2.9 in none and high, respectively. Among tissues, total SFA and MUFA were greater in s.c. adipose than LM, whereas total PUFA, n-6, and n-3 fatty acids and the n-6:n-3 ratio were lower. Trans-10 octadecenoic acid, VA, and CLA trans-10, cis-12 were greater (P

  7. Genetic variation in lipid desaturases and its impact on the development of human disease

    PubMed Central

    2010-01-01

    Perturbations in lipid metabolism characterize many of the chronic diseases currently plaguing our society, such as obesity, diabetes, and cardiovascular disease. Thus interventions that target plasma lipid levels remain a primary goal to manage these diseases. The determinants of plasma lipid levels are multi-factorial, consisting of both genetic and lifestyle components. Recent evidence indicates that fatty acid desaturases have an important role in defining plasma and tissue lipid profiles. This review will highlight the current state-of-knowledge regarding three desaturases (Scd-1, Fads1 and Fads2) and their potential roles in disease onset and development. Although research in rodent models has provided invaluable insight into the regulation and functions of these desaturases, the extent to which murine research can be translated to humans remains unclear. Evidence emerging from human-based research demonstrates that genetic variation in human desaturase genes affects enzyme activity and, consequently, disease risk factors. Moreover, this genetic variation may have a trans-generational effect via breastfeeding. Therefore inter-individual variation in desaturase function is attributed to both genetic and lifestyle components. As such, population-based research regarding the role of desaturases on disease risk is challenged by this complex gene-lifestyle paradigm. Unravelling the contribution of each component is paramount for understanding the inter-individual variation that exists in plasma lipid profiles, and will provide crucial information to develop personalized strategies to improve health management. PMID:20565855

  8. Knockdown of delta-5-desaturase promotes the anti-cancer activity of dihomo-γ-linolenic acid and enhances the efficacy of chemotherapy in colon cancer cells expressing COX-2.

    PubMed

    Xu, Yi; Yang, Xiaoyu; Zhao, Pinjing; Yang, Zhongyu; Yan, Changhui; Guo, Bin; Qian, Steven Y

    2016-07-01

    Cyclooxygenase (COX), commonly overexpressed in cancer cells, is a major lipid peroxidizing enzyme that metabolizes polyunsaturated fatty acids (ω-3s and ω-6s). The COX-catalyzed free radical peroxidation of arachidonic acid (ω-6) can produce deleterious metabolites (e.g. 2-series prostaglandins) that are implicated in cancer development. Thus, COX inhibition has been intensively investigated as a complementary therapeutic strategy for cancer. However, our previous study has demonstrated that a free radical-derived byproduct (8-hydroxyoctanoic acid) formed from COX-catalyzed peroxidation of dihomo-γ-linolenic acid (DGLA, the precursor of arachidonic acid) can inhibit colon cancer cell growth. We thus hypothesize that the commonly overexpressed COX in cancer (~90% of colon cancer patients) can be taken advantage to suppress cell growth by knocking down delta-5-desaturase (D5D, a key enzyme that converts DGLA to arachidonic acid). In addition, D5D knockdown along with DGLA supplement may enhance the efficacy of chemotherapeutic drugs. After knocking down D5D in HCA-7 colony 29 cells and HT-29 cells (human colon cancer cell lines with high and low COX levels, respectively), the antitumor activity of DGLA was significantly enhanced along with the formation of a threshold range (~0.5-1.0μM) of 8-hydroxyoctanoic acid. In contrast, DGLA treatment did not inhibit cell growth when D5D was not knocked down and only limited amount of 8-hydroxyoctanoic acid was formed. D5D knockdown along with DGLA treatment also enhanced the cytotoxicities of various chemotherapeutic drugs, including 5-fluorouracil, regorafenib, and irinotecan, potentially through the activation of pro-apoptotic proteins, e.g. p53 and caspase 9. For the first time, we have demonstrated that the overexpressed COX in cancer cells can be utilized in suppressing cancer cell growth. This finding may provide a new option besides COX inhibition to optimize cancer therapy. The outcome of this translational

  9. Knockdown of delta-5-desaturase promotes the anti-cancer activity of dihomo-γ-linolenic acid and enhances the efficacy of chemotherapy in colon cancer cells expressing COX-2

    PubMed Central

    Xu, Yi; Yang, Xiaoyu; Zhao, Pinjing; Yang, Zhongyu; Yan, Changhui; Guo, Bin; Qian, Steven Y.

    2016-01-01

    Cyclooxygenase (COX), commonly overexpressed in cancer cells, is a major lipid peroxidizing enzyme that metabolizes polyunsaturated fatty acids (ω-3s and ω-6s). The COX-catalyzed free radical peroxidation of arachidonic acid (ω-6) can produce deleterious metabolites (e.g. 2-series prostaglandins) that are implicated in cancer development. Thus, COX inhibition has been intensively investigated as a complementary therapeutic strategy for cancer. However, our previous study has demonstrated that a free radical-derived by product (8-hydroxyoctanoic acid) formed from COX-catalyzed peroxidation of dihomo-γ-linolenic acid (DGLA, the precursor of arachidonic acid) can inhibit colon cancer cell growth. We thus hypothesize that the commonly overexpressed COX in cancer (~90% of colon cancer patients) can be taken advantage to suppress cell growth by knocking down delta-5-desaturase (D5D, a key enzyme that converts DGLA to arachidonic acid). In addition, D5D knockdown along with DGLA supplement may enhance the efficacy of chemotherapeutic drugs. After knocking down D5D in HCA-7 colony 29 cells and HT-29 cells (human colon cancer cell lines with high and low COX levels, respectively), the antitumor activity of DGLA was significantly enhanced along with the formation of a threshold range (~0.5–1.0 µM) of 8-hydroxyoctanoic acid. In contrast, DGLA treatment did not inhibit cell growth when D5D was not knocked down and only limited amount of 8-hydroxyoctanoic acid was formed. D5D knockdown along with DGLA treatment also enhanced the cytotoxicities of various chemotherapeutic drugs, including 5-fluorouracil, regorafenib, and irinotecan, potentially through the activation of pro-apoptotic proteins, e.g. p53 and caspase 9. For the first time, we have demonstrated that the overexpressed COX in cancer cells can be utilized in suppressing cancer cell growth. This finding may provide a new option besides COX inhibition to optimize cancer therapy. The outcome of this translational

  10. Regulation of tissue LC-PUFA contents, Δ6 fatty acyl desaturase (FADS2) gene expression and the methylation of the putative FADS2 gene promoter by different dietary fatty acid profiles in Japanese seabass (Lateolabrax japonicus).

    PubMed

    Xu, Houguo; Dong, Xiaojing; Ai, Qinghui; Mai, Kangsen; Xu, Wei; Zhang, Yanjiao; Zuo, Rantao

    2014-01-01

    The present study was conducted to evaluate the influences of different dietary fatty acid profiles on the tissue content and biosynthesis of LC-PUFA in a euryhaline species Japanese seabass reared in seawater. Six diets were prepared, each with a characteristic fatty acid: Diet PA: Palmitic acid (C16:0); Diet SA: Stearic acid (C18:0); Diet OA: Oleic acid (C18:1n-9); Diet LNA: α-linolenic acid (C18:3n-3); Diet N-3 LC-PUFA: n-3 LC-PUFA (DHA+EPA); Diet FO: the fish oil control. A 10-week feeding trial was conducted using juvenile fish (29.53 ± 0.86 g). The results showed that Japanese seabass had limited capacity to synthesize LC-PUFA and fish fed PA, SA, OA and LNA showed significantly lower tissue n-3 LC-PUFA contents compared to fish fed N-3 LC-PUFA and FO. The putative gene promoter and full-length cDNA of FADS2 was cloned and characterized. The protein sequence was confirmed to be homologous to FADS2s of marine teleosts and possessed all the characteristic features of microsomal fatty acid desaturases. The FADS2 transcript levels in liver of fish fed N-3 LC-PUFA and FO were significantly lower than those in fish fed other diets except LNA while Diet PA significantly up-regulated the FADS2 gene expression compared to Diet LNA, N-3 LC-PUFA and FO. Inversely, fish fed N-3 LC-PUFA and FO showed significantly higher promoter methylation rates of FADS2 gene compared to fish fed the LC-PUFA deficient diets. These results suggested that Japanese seabass had low LC-PUFA synthesis capacity and LC-PUFA deficient diets caused significantly reduced tissue n-3 LC-PUFA contents. The liver gene expression of FADS2 was up-regulated in groups enriched in C16:0, C18:0 and C18:1n-9 respectively but not in the group enriched in C18:3n-3 compared to groups with high n-3 LC-PUFA contents. The FADS2 gene expression regulated by dietary fatty acids was significantly negatively correlated with the methylation rate of putative FADS2 gene promoter.

  11. Cloning and expression analysis of phytoene desaturase and ζ-carotene desaturase genes in Carica papaya.

    PubMed

    Yan, P; Gao, X Z; Shen, W T; Zhou, P

    2011-02-01

    The fruit flesh color of papaya is an important nutritional quality trait and is due to the accumulation of carotenoid. To elucidate the carotenoid biosynthesis pathway in Carica papaya, the phytoene desaturase (PDS) and the ζ-carotene desaturase (ZDS) genes were isolated from papaya (named CpPDS and CpZDS) using the rapid amplification of cDNA ends (RACE) approach, and their expression levels were investigated in red- and yellow-fleshed papaya varieties. CpPDS contains a 1749 bp open reading frame coding for 583 amino acids, while CpZDS contains a 1716 bp open reading frame coding for 572 amino acids. The deduced CpPDS and CpZDS proteins contain a conserved dinucleotide-binding site at the N-terminus and a carotenoid-binding domain at the C-terminus. Papaya genome sequence analysis revealed that CpPDS and CpZDS are single copy; the CpPDS was mapped to papaya chromosome LG6, and the CpZDS was mapped to chromosome LG3. Quantitative PCR showed that both CpPDS and CpZDS were expressed in all tissues examined with the highest expression in maturing fruits, and that the expression of CpPDS and CpZDS were higher in red-fleshed fruits than in yellow-fleshed fruits. These results indicated that the differential accumulation of carotenoids in red- and yellow-fleshed papaya varieties might be partly explained by the transcriptional level of CpPDS and CpZDS.

  12. A modified PCR protocol for consistent amplification of fatty acid desaturase (FAD) alleles in marker-assisted backcross breeding for high oleic trait in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High oleic acid, such as is found in olive oil, is desirable for the healthy cholesterol-lowering benefits. The oxidative stability of the oil with high oleic acid also gives longer “shelve life” for peanut products. These benefits drive the breeding effort toward developing high oleic peanuts worl...

  13. Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed.

    PubMed

    Cahoon, E B; Coughlan, S J; Shanklin, J

    1997-04-01

    A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1delta9)* and cis-vaccenic (18:1delta11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed delta9 desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known delta9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized delta9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a delta9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

  14. Stearoyl coenzyme A desaturase enzyme activity and mRNA levels are not different in subcutaneous adipose tissue from Angus and American Wagyu steers.

    PubMed

    Cameron, P J; Rogers, M; Oman, J; May, S G; Lunt, D K; Smith, S B

    1994-10-01

    We proposed that greater stearoyl coenzyme A (CoA) desaturase enzyme activity caused the elevated monounsaturated fatty acids observed in American Wagyu adipose tissue. Stearoyl CoA desaturase mRNA concentrations and enzyme activities were measured in subcutaneous adipose samples from Angus (n = 5) and American Wagyu (n = 5), fed to the Japanese market end point. A rat liver stearoyl CoA desaturase cDNA clone was used to measure the relative amounts of stearoyl CoA desaturase mRNA. Enzyme activities and mRNA concentrations, as measured by laser densitometry of slot-blot autoradiograms, were not significantly different between the two breeds at this stage of growth. This investigation has demonstrated that, at this stage of maturity, differences in fatty acid composition between Angus and American Wagyu steers cannot be attributed to differences in stearoyl CoA desaturase enzyme activity.

  15. Immunocytochemical localization of acyl-lipid desaturases in cyanobacterial cells: evidence that both thylakoid membranes and cytoplasmic membranes are sites of lipid desaturation.

    PubMed Central

    Mustardy, L; Los, D A; Gombos, Z; Murata, N

    1996-01-01

    There are four acyl-lipid desaturases in the cyanobacterium Synechocystis sp. PCC 6803. Each of these desaturases introduces a double bond at a specific position, such as the Delta6, Delta9, Delta12, or omicron3 position, in C18 fatty acids. The localization of the desaturases in cyanobacterial cells was examined immunocytochemically with antibodies raised against synthetic oligopeptides that corresponded to the carboxyl-terminal regions of the desaturases. All four desaturases appeared to be located in the regions of both the cytoplasmic and the thylakoid membranes. These findings suggest that fatty acid desaturation of membrane lipids takes place in the thylakoid membranes as well as in the cytoplasmic membranes. Images Fig. 1 Fig. 2 Fig. 3 PMID:11607709

  16. Addition of an N-terminal epitope tag significantly increases the activity of plant fatty acid desaturases expressed in yeast cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saccharomyces cerevisiae shows great potential for development of bioreactor systems geared towards the production of high-value lipids such as polyunsaturated omega-3 fatty acids, the yields of which are largely dependent on the activity of ectopically-expressed enzymes. Here we show that the addit...

  17. FAD2 and FAD3 Desaturases Form Heterodimers That Facilitate Metabolic Channeling in Vivo *

    PubMed Central

    Lou, Ying; Schwender, Jorg; Shanklin, John

    2014-01-01

    Plant desaturases comprise two independently evolved classes, a structurally well characterized soluble class responsible for the production of monoenes in the plastids of higher plants and the poorly structurally characterized integral membrane class that has members in the plastid and endoplasmic reticulum that are responsible for producing mono- and polyunsaturated fatty acids. Both require iron and oxygen for activity and are inhibited by azide and cyanide underscoring their common chemical imperatives. We previously showed that the Δ9 acyl-CoA integral membrane desaturase Ole1p from Saccharomyces cerevisiae exhibits dimeric organization, like the soluble plastidial acyl-ACP desaturases. Here we use two independent bimolecular complementation assays, i.e. yeast two-hybrid analysis and Arabidopsis leaf protoplast split luciferase assay, to demonstrate that members of the plant integral membrane fatty acid desaturase (FAD) family, FAD2, FAD3, FAD6, FAD7, and FAD8, self-associate. Further, the endoplasmic reticulum-localized desaturase FAD2 can associate with FAD3, as can the plastid-localized FAD6 desaturase with either FAD7 or FAD8. These pairings appear to be specific because pairs such as FAD3 and FAD7 (or FAD8) and FAD2 and FAD6 do not interact despite their high amino acid similarity. These results are consistent also with their known endoplasmic reticulum and plastid subcellular localizations. Chemical cross-linking experiments confirm that FAD2 and FAD3 can form dimers like the yeast Ole1p and, when coexpressed, can form FAD2-FAD3 heterodimers. Metabolic flux analysis of yeast coexpressing FAD2 and FAD3 indicates that heterodimers can form a metabolic channel in which 18:1-PC is converted to 18:3-PC without releasing a free 18:2-PC intermediate. PMID:24811169

  18. FAD2 and FAD3 desaturases form heterodimers that facilitate metabolic channeling in vivo.

    PubMed

    Lou, Ying; Schwender, Jorg; Shanklin, John

    2014-06-27

    Plant desaturases comprise two independently evolved classes, a structurally well characterized soluble class responsible for the production of monoenes in the plastids of higher plants and the poorly structurally characterized integral membrane class that has members in the plastid and endoplasmic reticulum that are responsible for producing mono- and polyunsaturated fatty acids. Both require iron and oxygen for activity and are inhibited by azide and cyanide underscoring their common chemical imperatives. We previously showed that the Δ(9) acyl-CoA integral membrane desaturase Ole1p from Saccharomyces cerevisiae exhibits dimeric organization, like the soluble plastidial acyl-ACP desaturases. Here we use two independent bimolecular complementation assays, i.e. yeast two-hybrid analysis and Arabidopsis leaf protoplast split luciferase assay, to demonstrate that members of the plant integral membrane fatty acid desaturase (FAD) family, FAD2, FAD3, FAD6, FAD7, and FAD8, self-associate. Further, the endoplasmic reticulum-localized desaturase FAD2 can associate with FAD3, as can the plastid-localized FAD6 desaturase with either FAD7 or FAD8. These pairings appear to be specific because pairs such as FAD3 and FAD7 (or FAD8) and FAD2 and FAD6 do not interact despite their high amino acid similarity. These results are consistent also with their known endoplasmic reticulum and plastid subcellular localizations. Chemical cross-linking experiments confirm that FAD2 and FAD3 can form dimers like the yeast Ole1p and, when coexpressed, can form FAD2-FAD3 heterodimers. Metabolic flux analysis of yeast coexpressing FAD2 and FAD3 indicates that heterodimers can form a metabolic channel in which 18:1-PC is converted to 18:3-PC without releasing a free 18:2-PC intermediate.

  19. Identification and functional analysis of a phytoene desaturase gene from the extremely radioresistant bacterium Deinococcus radiodurans.

    PubMed

    Xu, Zhenjian; Tian, Bing; Sun, Zongtao; Lin, Jun; Hua, Yuejin

    2007-05-01

    The phytoene-related desaturases are the key enzymes in the carotenoid biosynthetic pathway. The gene encoding phytoene desaturase in the deinoxanthin synthesis pathway of Deinococcus radiodurans was identified and characterized. Two putative phytoene desaturase homologues (DR0861 and DR0810) were identified by analysis of conserved amino acid regions, and the former displayed the highest identity (68 %) with phytoene desaturase of the cyanobacterium Gloeobacter violaceus. DR0861 gene knockout and dinucleotide-binding motif deletion resulted in the arrest of lycopene synthesis and the accumulation of phytoene. The colourless DR0861 knockout mutant became more sensitive to acute ionizing radiation and oxygen stress. Complementation of the mutant with a heterologous or homologous gene restored its pigment and resistance. The desaturase activity of DR0861 (crtI) was further confirmed by the assay of enzyme activity in vitro and heterologous expression in Escherichia coli containing crtE and crtB genes (responsible for phytoene synthesis) from Erwinia uredovora. In addition, the amount of lycopene synthesis in E. coli resulting from the expression of crtI from D. radiodurans was determined, and this had significant dose-dependent effects on the survival rate of E. coli exposed to hydrogen peroxide and ionizing radiation.

  20. Evolution of the integral membrane desaturase gene family in moths and flies.

    PubMed Central

    Knipple, Douglas C; Rosenfield, Claire-Lise; Nielsen, Rasmus; You, Kyung Man; Jeong, Seong Eun

    2002-01-01

    Lepidopteran insects use sex pheromones derived from fatty acids in their species-specific mate recognition system. Desaturases play a particularly prominent role in the generation of structural diversity in lepidopteran pheromone biosynthesis as a result of the diverse enzymatic properties they have evolved. These enzymes are homologous to the integral membrane desaturases, which play a primary role in cold adaptation in eukaryotic cells. In this investigation, we screened for desaturase-encoding sequences in pheromone glands of adult females of eight lepidopteran species. We found, on average, six unique desaturase-encoding sequences in moth pheromone glands, the same number as is found in the genome database of the fly, Drosophila melanogaster, vs. only one to three in other characterized eukaryotic genomes. The latter observation suggests the expansion of this gene family in insects before the divergence of lepidopteran and dipteran lineages. We present the inferred homology relationships among these sequences, analyze nonsynonymous and synonymous substitution rates for evidence of positive selection, identify sequence and structural correlates of three lineages containing characterized enzymatically distinct desaturases, and discuss the evolution of this sequence family in insects. PMID:12524345

  1. Evidence that the Yeast Desaturase Ole1p Exists as a Dimer In Vivo

    SciTech Connect

    Lou, Y.; Shanklin, J.

    2010-06-18

    Desaturase enzymes are composed of two classes, the structurally well characterized soluble class found predominantly in the plastids of higher plants and the more widely distributed but poorly structurally defined integral membrane class. Despite their distinct evolutionary origins, the two classes both require an iron cofactor and molecular oxygen for activity and are inhibited by azide and cyanide, suggesting strong mechanistic similarities. The fact that the soluble desaturase is active as a homodimer prompted us test the hypothesis that an archetypal integral membrane desaturase from Saccharomyces cerevisiae, the {Delta}{sup o}-acyl-Co-A desaturase Ole1p, also exhibits a dimeric organization. Ole1p was chosen because it is one of the best characterized integral membrane desaturase and because it retains activity when fused with epitope tags. FLAG-Ole1p was detected by Western blotting of immunoprecipitates in which anti-Myc antibodies were used for capture from yeast extracts co-expressing Ole1p-Myc and Ole1p-FLAG. Interaction was confirmed by two independent bimolecular complementation assays (i.e. the split ubiquitin system and the split luciferase system). Co-expression of active and inactive Ole1p subunits resulted in an {approx}75% suppression of the accumulation of palmitoleic acid, demonstrating that the physiologically active form of Ole1p in vivo is the dimer in which both protomers must be functional.

  2. Factors affecting the palmitoyl-coenzyme A desaturase of Saccharomyces cerevisiae

    NASA Technical Reports Server (NTRS)

    Klein, H. P.; Volkmann, C. M.

    1975-01-01

    The activity and stability of the palmitoyl-coenzyme A (CoA) desaturase complex of Saccharomyces cerevisiae was influenced by several factors. Cells, grown nonaerobically and then incubated with glucose, either in air or under N2, showed a marked increase in desaturase activity. Cycloheximide, added during such incubations, prevented the increase in activity, suggesting de novo synthesis. The stability of the desaturase from cells grown nonaerobically was affected by subsequent treatment of the cells; enzyme from freshly harvested cells, or from cells that were then shaken under nitrogen, readily lost activity upon washing or during density gradient analysis, whereas aerated cells, in the presence or absence of glucose, yielded stable enzyme preparations. The loss of activity in nonaerobic preparations could be reversed by adding soluble supernatant from these homogenates and could be prevented by growing the cells in the presence of palmitoleic acid and ergosterol, but not with several other lipids tested.

  3. Transcriptional analysis reveals a high impact of conjugated linoleic acid on stearoyl-Coenzyme A desaturase 1 mRNA expression in mice gastrocnemius muscle.

    PubMed

    Parra, Pilar; Serra, Francisca; Palou, Andreu

    2012-10-01

    We examined the potential implication of skeletal muscle in the fat-lowering effect observed in mice treated with moderate doses of CLA. In experiment 1, mice fed with a standard-fat diet were orally treated with sunflower oil (control) and 3 or 10 mg CLA mixture/day for 37 days. In experiment 2, mice were fed with a high-fat diet for 65 days. For the first 30 days, they received the same doses as in experiment 1 and, from that time onwards, animals received double doses. Gene expression of key proteins involved in fatty acid transport, oxidation, regulation of lipid and carbohydrate utilization, composition of muscle fiber, and thermogenesis were determined and, in most of them, no major impact of CLA was seen. Therefore, enhancement of fatty acid oxidation in muscle did not seem to contribute to the antiobesity effect of CLA as seen in other studies with higher CLA doses. However, a strong induction of classically associated lipogenic genes such as Fasn (up to twofold) and, particularly, Scd1 (up to ninefold) was found. This activation could contribute to a protective role in muscle cells, since expression of ER stress markers was decreased and inversely correlated with the induction of Scd1.

  4. Cloning and characterization of a Δ9-desaturase gene of the Antarctic fish Chionodraco hamatus and Trematomus bernacchii.

    PubMed

    Porta, Amalia; Fortino, Vittorio; Armenante, Annunziata; Maresca, Bruno

    2013-04-01

    Chionodraco hamatus and Trematomus bernacchii are perciforms, members of the fish suborder Notothenioidei that live in the Antarctic Ocean and experience very cold and persistent environmental temperature. These fish have biochemical and molecular features that allow them to live at these extreme cold temperatures. Fine tuning of the level of unsaturated fatty acids content in membrane is a key mechanism of living organisms to adapt to cold and high temperatures. Desaturases are key enzymes that synthesize unsaturated fatty acyl-CoAs from saturated fatty acids. We cloned and sequenced a Δ(9)-desaturase gene and its cDNA of C. hamatus, and the cDNA of T. bernacchii. The coded proteins are virtually identical and share homology to other Δ(9)-desaturase fish sequences. These proteins contain, in the first trans-membrane domain, two cysteine residues that may form a disulfur bond present in the corresponding membrane region of Δ(9)-desaturase proteins of other Antarctic fish but not in Eleginops maclovinus that experiences higher environmental temperatures and in all other Δ(9)-desaturase genes of mammals present in data bases. C. hamatus Δ(9)-desaturase gene complements a Saccharomyces cerevisiae mutant lacking Δ(9)-desaturase (Ole1) gene. Analysis of sequence homology of the trans-membrane domains of Δ(9)-desaturase and the cytoplasmic region of the same proteins of Antarctic fish, non-Antarctic fish and mammals suggest that the significant differences found in the homologous sequences of the first trans-membrane domain may be due to the specific lipid content of their membrane.

  5. Cloning and characterization of a delta-6 desaturase encoding gene from Nannochloropsis oculata

    NASA Astrophysics Data System (ADS)

    Ma, Xiaolei; Yu, Jianzhong; Zhu, Baohua; Pan, Kehou; Pan, Jin; Yang, Guanpin

    2011-03-01

    A gene ( NANOC-D6D) encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata (Droop) D. J. Hibberd (Eustigmatophyceae). The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids (LCPUFAs), including eicosapentaenoic acid (20:5n-3, EPA). The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVScl to verify the substrate specificity of NANOC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid (LA) and α-linolenic acid (ALA).

  6. Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

    SciTech Connect

    Alloatti, Andres; Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A.; Altabe, Silvia G.; Deumer, Gladys; Wallemacq, Pierre; Michels, Paul A.M.; Uttaro, Antonio D.

    2011-08-26

    Highlights: {yields} Inhibiting {Delta}9 desaturase drastically changes T. brucei's fatty-acid composition. {yields} Isoxyl specifically inhibits the {Delta}9 desaturase causing a growth arrest. {yields} RNA interference of desaturase expression causes a similar effect. {yields} Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. {yields} 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC{sub 50}) of PCF was 1.0 {+-} 0.2 {mu}M for Isoxyl and 5 {+-} 2 {mu}M for 10-TS, whereas BSF appeared more susceptible with EC{sub 50} values 0.10 {+-} 0.03 {mu}M (Isoxyl) and 1.0 {+-} 0.6 {mu}M (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

  7. An oleate 12-hydroxylase from Ricinus communis L. is a fatty acyl desaturase homolog.

    PubMed Central

    van de Loo, F J; Broun, P; Turner, S; Somerville, C

    1995-01-01

    Recent spectroscopic evidence implicating a binuclear iron site at the reaction center of fatty acyl desaturases suggested to us that certain fatty acyl hydroxylases may share significant amino acid sequence similarity with desaturases. To test this theory, we prepared a cDNA library from developing endosperm of the castor-oil plant (Ricinus communis L.) and obtained partial nucleotide sequences for 468 anonymous clones that were not expressed at high levels in leaves, a tissue deficient in 12-hydroxyoleic acid. This resulted in the identification of several cDNA clones encoding a polypeptide of 387 amino acids with a predicted molecular weight of 44,407 and with approximately 67% sequence homology to microsomal oleate desaturase from Arabidopsis. Expression of a full-length clone under control of the cauliflower mosaic virus 35S promoter in transgenic tobacco resulted in the accumulation of low levels of 12-hydroxyoleic acid in seeds, indicating that the clone encodes the castor oleate hydroxylase. These results suggest that fatty acyl desaturases and hydroxylases share similar reaction mechanisms and provide an example of enzyme evolution. Images Fig. 3 Fig. 4 Fig. 5 PMID:7624314

  8. An oleate 12-hydroxylase from Ricinus communis L. is a fatty acyl desaturase homolog

    SciTech Connect

    Van De Loo, F.J.; Broun, P.; Turner, S.; Somerville, C.

    1995-07-18

    Recent spectroscopic evidence implicating a binuclear iron site at the reaction center of fatty acyl desaturases suggested to us that certain fatty acyl hydroxylases may share significant amino acid sequence similarity with desaturases. To test this theory, we prepared a cDNA library from developing endosperm of the castor-oil plant (Ricinus communis L.) and obtained partial nucleotide sequences for 468 anonymous clones that were not expressed at high levels in leaves, a tissue deficient in 12-hydroxyoleic acid. This resulted in the identification of several cDNA clones encoding a polypeptide of 387 amino acids with a predicted molecular weight of 44,407 and with {approx}67% sequence homology to microsomal oleate desaturase from Arabidopsis. Expression of a full-length clone under control of the cauliflower mosaic virus 35S promoter in transgenic tobacco resulted in the accumulation of low levels of 12-hydroxyoleic acid in seeds, indicating that the clone encodes the castor oleate hydroxylase. These results suggest that fatty acyl desaturases and hydroxylases share similar reaction mechanisms and provide an example of enzyme evolution. 26 refs., 6 figs., 1 tab.

  9. Identification and Functional Analysis of Delta-9 Desaturase, a Key Enzyme in PUFA Synthesis, Isolated from the Oleaginous Diatom Fistulifera

    PubMed Central

    Muto, Masaki; Kubota, Chihiro; Tanaka, Masayoshi; Satoh, Akira; Matsumoto, Mitsufumi; Yoshino, Tomoko; Tanaka, Tsuyoshi

    2013-01-01

    Oleaginous microalgae are one of the promising resource of nonedible biodiesel fuel (BDF) feed stock alternatives. Now a challenge task is the decrease of the long-chain polyunsaturated fatty acids (PUFAs) content affecting on the BDF oxidative stability by using gene manipulation techniques. However, only the limited knowledge has been available concerning the fatty acid and PUFA synthesis pathways in microalgae. Especially, the function of Δ9 desaturase, which is a key enzyme in PUFA synthesis pathway, has not been determined in diatom. In this study, 4 Δ9 desaturase genes (fD9desA, fD9desB, fD9desC and fD9desD) from the oleaginous diatom Fistulifera were newly isolated and functionally characterized. The putative Δ9 acyl-CoA desaturases in the endoplasmic reticulum (ER) showed 3 histidine clusters that are well-conserved motifs in the typical Δ9 desaturase. Furthermore, the function of these Δ9 desaturases was confirmed in the Saccharomyces cerevisiae ole1 gene deletion mutant (Δole1). All the putative Δ9 acyl-CoA desaturases showed Δ9 desaturation activity for C16∶0 fatty acids; fD9desA and fD9desB also showed desaturation activity for C18∶0 fatty acids. This study represents the first functional analysis of Δ9 desaturases from oleaginous microalgae and from diatoms as the first enzyme to introduce a double bond in saturated fatty acids during PUFA synthesis. The findings will provide beneficial insights into applying metabolic engineering processes to suppressing PUFA synthesis in this oleaginous microalgal strain. PMID:24039966

  10. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs

    SciTech Connect

    Shanklin, J.; Somerville, C. )

    1991-03-15

    Stearoyl-acyl-carrier-protein (ACP) desaturase was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cDNA clones from Ricinus communis (castor) seed and Cucumis sativus (cucumber). The nucleotide sequence of the castor clone pRCD1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kDa. The cucumber clone pCSD1 encoded a homologous 396-amino acid protein with 88% amino acid identity to the castor clone. Expression of pRCD1 in Saccharomyces cerevisiae resulted in the accumulation of a functional stearoyl-ACP desaturase, demonstrating that the introduction of this single gene product was sufficient to confer soluble desaturase activity to yeast. There was a 48-residue region of 29% amino acid sequence identity between residues 53 and 101 of the castor desaturase and the proximal border of the dehydratase region of the fatty acid synthase from yeast. Stearoyl-ACP mRNA was present at substantially higher levels in developing seeds than in leaf and root tissue, suggesting that expression of the {Delta}{sup 9} desaturase is developmentally regulated.

  11. Multiple Δ11-desaturase genes selectively used for sex pheromone biosynthesis are conserved in Ostrinia moth genomes.

    PubMed

    Fujii, Takeshi; Yasukochi, Yuji; Rong, Yu; Matsuo, Takashi; Ishikawa, Yukio

    2015-06-01

    Regulation of the expression of fatty acyl-CoA desaturases, which introduce a double bond into the fatty acid moiety of the substrate, is crucial for the production of species-specific sex pheromones in moths. In Ostrinia moths, two distinct Δ11-desaturases and a Δ14-desaturase are known to be selectively used in the biosynthesis of sex pheromones. Of the two Δ11-desaturases, one identified from Ostrinia nubilalis and Ostrinia scapulalis, Z/EΔ11, forms the Z and E isomers of a double bond at position 11, whereas the other identified from Ostrinia latipennis, LATPG1(=EΔ11), exclusively forms an E double bond at position 11. Since the retroposon(ezi)-fused, non-functional Δ11-desaturase gene, ezi-Δ11α, in the genomes of O. nubilalis and O. furnacalis was previously suggested to be an orthologue of latpg1, we here explored Z/EΔ11 orthologues in the genome of O. latipennis. We newly identified two Δ11-desaturase genes, latpg2 and latpg3, which were orthologous to ezi-Δ11β and Z/EΔ11, respectively. We found that an ezi-like element was integrated in intron 1 of latpg1, and confirmed that only latpg1 was expressed in the pheromone gland of O. latipennis. Thus, at least three Δ11-desaturase genes are present in the genome of O. latipennis, and latpg1 is selectively transcribed in the pheromone gland of this moth. The non-functionality of ezi-inserted desaturase genes in O. nubilalis and O. furnacalis may not be a direct consequence of the insertion of an ezi- or ezi-like element into the gene.

  12. Functional identification of a delta8-sphingolipid desaturase from Borago officinalis.

    PubMed

    Sperling, P; Libisch, B; Zähringer, U; Napier, J A; Heinz, E

    2001-04-15

    The similarities between delta12- and delta5-fatty acyl desaturase sequences were used to construct degenerate primers for PCR experiments with cDNA transcribed from mRNA of developing borage seeds. Screening of a borage seed cDNA library with an amplified DNA fragment resulted in the isolation of a full-length cDNA corresponding to a deduced open-reading frame of 446 amino acids. The protein showed high similarity to plant delta8-sphingolipid desaturases as well as to the delta6-fatty acyl desaturase from Borago officinalis. The sequence is characterized by the presence of a N-terminal cytochrome b5 domain. Expression of this open-reading frame in Saccharomyces cerevisiae resulted in the formation of delta8-trans/cis-phytosphingenines not present in wild-type cells, as shown by HPLC analysis of sphingoid bases as their dinitrophenyl derivatives. GLC-MS analysis of the methylated di-O-trimethylsilyl ether derivatives confirmed the presence of delta8-stereoisomers of C18- and C20-phytosphingenine. Furthermore, Northern blotting showed that the gene encoding a stereo-unselective delta8-sphingolipid desaturase is primarily expressed in young borage leaves.

  13. Cloning and knockout of phytoene desaturase gene in Sphingomonas elodea ATCC 31461 for economic recovery of gellan gum.

    PubMed

    Zhu, Liang; Wu, Xuechang; Li, Ou; Chen, Yamin; Qian, Chaodong; Teng, Yi; Tao, Xianglin; Gao, Haichun

    2011-09-01

    A gene encoding phytoene desaturase (crtI) in the carotenoid biosynthetic pathway of Sphingomonas elodea ATCC 31461, an industrial gellan gum-producing strain, was cloned and identified. This gene is predicted to encode a 492-amino acid protein with significant homology to the phytoene desaturase of other carotenogenic organisms. Knockout of crtI gene blocked yellow carotenoid pigment synthesis and resulted in the accumulation of colorless phytoene, confirming that it encodes phytoene desaturase. Further research indicates that the yield of gellan gum production by crtI gene knockout mutants is almost the same as that by the wild-type strain. In addition, a recovery method based on the colorless fermentation broth of the crtI gene knockout mutant was investigated. Compared to the volume of alcohol for the parent strain, much less alcohol (30%) is required in this recovery process; thus, the costs of downstream purification of gellan gum can be substantially reduced.

  14. Stabilization of the yeast desaturase system by low levels of oxygen

    NASA Technical Reports Server (NTRS)

    Volkmann, C. M.; Klein, H. P.

    1983-01-01

    The stability of particulate palmitoyl-CoA desaturase preparations from anaerobically grown yeast cells was increased by exposure to low levels of oxygen. The stabilizing effect of oxygen may be based upon the increased amounts of palmitoleic acid and ergosterol that become available to the cells. These results suggest the evolutinary appearance of this system at a time when atmospheric oxygen was at a low level.

  15. Bioengineering resistance to phytoene desaturase inhibitors in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three natural somatic mutations at codon 304 of the phytoene desaturase gene (pds) of Hydrilla verticillata ( L. f. Royle) have been reported to provide resistance to the herbicide fluridone. We substituted the arginine 304 present in the wild-type H. verticillata phytoene desaturase (PDS) with all...

  16. Cloning, tissue expression analysis, and functional characterization of two Δ6-desaturase variants of sea bass (Dicentrarchus labrax L.).

    PubMed

    Santigosa, Ester; Geay, Florian; Tonon, Thierry; Le Delliou, Herve; Kuhl, Heiner; Reinhardt, Richard; Corcos, Laurent; Cahu, Chantal; Zambonino-Infante, José Luis; Mazurais, David

    2011-02-01

    Fish are the main source of the n-3 highly unsaturated fatty acids, which are crucial for human health. Their synthesis from C(18) precursors is mediated by desaturases and elongases, but the activity of these enzymes has not been conclusively established in marine fish species. This study reports the cloning, tissue expression, and functional characterization of a sea bass (Dicentrarchus labrax L.) Δ6-desaturase and one of its splicing variants. Two cDNAs with open reading frames of 1,346 and 1,354 bp were cloned and named D6D and D6D-V, respectively. Both deduced protein sequences (445 and 387 amino acids, respectively) contained two transmembrane regions and the N-terminal cytochrome b(5) domain with the HPGG motif characteristic of microsomal desaturases. D6D presents three histidine-rich regions, whereas in D6D-V, an insertion of eight nucleotides in the boundaries of exons 10 and 11 modified the third histidine-rich domain and led to insertion of a premature STOP codon, resulting in a shorter predicted protein. Quantitative real-time polymerase chain reaction assay of gene expression showed that D6D was highly expressed in the brain and intestine, and to a lesser extent, in muscle and liver; meanwhile, D6D-V was expressed in all tissues tested, but at level at least 200-fold lower than D6D. Functional analysis in yeast showed that sea bass D6D encodes a fully functional Δ6-desaturase with no residual Δ5-desaturase activity. This desaturase does not exhibit a clear preference for n-3 versus n-6 C(18) substrates. Interestingly, D6D-V is a nonfunctional protein, suggesting that the C-terminal end is indispensable for protein activity.

  17. Isolation of a Δ5 desaturase gene from Euglena gracilis and functional dissection of its HPGG and HDASH motifs.

    PubMed

    Walters Pollak, Dana; Bostick, Michael W; Yoon, Hyeryoung; Wang, Jamie; Hollerbach, Dieter H; He, Hongxian; Damude, Howard G; Zhang, Hongxiang; Yadav, Narendra S; Hong, Seung-Pyo; Sharpe, Pamela; Xue, Zhixiong; Zhu, Quinn

    2012-09-01

    Delta (Δ) 5 desaturase is a key enzyme for the biosynthesis of health-beneficial long chain polyunsaturated fatty acids such as arachidonic acid (ARA, C20:4n-6), eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) via the "desaturation and elongation" pathways. A full length Δ5 desaturase gene from Euglena gracilis (EgΔ5D) was isolated by cloning the products of polymerase chain reaction with degenerate oligonucleotides as primers, followed by 5' and 3' rapid amplification of cDNA ends. The whole coding region of EgΔ5D was 1,350 nucleotides in length and encoded a polypeptide of 449 amino acids. BlastP search showed that EgΔ5D has about 39 % identity with a Δ5 desaturase of Phaeodactylum tricornutum. In a genetically modified dihomo-gamma-linoleic acid (DGLA, C20:3n-6) producing Yarrowia lipolytica strain, EgΔ5D had strong Δ5 desaturase activity with DGLA to ARA conversion of more than 24 %. Functional dissection of its HPGG and HDASH motifs demonstrated that both motifs were important, but not necessary in the exact form as encoded for the enzyme activity of EgΔ5D. A double mutant EgΔ5D-34G158G with altered sequences within both HPGG and HDASH motifs was generated and exhibited Δ5 desaturase activity similar to the wild type EgΔ5D. Codon optimization of the N-terminal region of EgΔ5D-34G158G and substitution of the arginine with serine at residue 347 improved substrate conversion to 27.6 %.

  18. A bifunctional delta-fatty acyl acetylenase/desaturase from the moss Ceratodon purpureus. A new member of the cytochrome b5 superfamily.

    PubMed

    Sperling, P; Lee, M; Girke, T; Zähringer, U; Stymne, S; Heinz, E

    2000-06-01

    Many plant genes have been cloned that encode regioselective desaturases catalyzing the formation of cis-unsaturated fatty acids. However, very few genes have been cloned that encode enzymes catalyzing the formation of the functional groups found in unusual fatty acids (e.g. hydroxy, epoxy or acetylenic fatty acids). Here, we describe the characterization of an acetylenase from the moss Ceratodon purpureus with a regioselectivity differing from the previously described Delta12-acetylenase. The gene encoding this protein, together with a Delta6-desaturase, was cloned by a PCR-based approach with primers derived from conserved regions in Delta5-, Delta6-fatty-acid desaturases and Delta8-sphingolipid desaturases. The proteins that are encoded by the two cloned cDNAs are likely to consist of a N-terminal extension of unknown function, a cytochrome b5-domain, and a C-terminal domain that is similar to acyl lipid desaturases with characteristic histidine boxes. The proteins were highly homologous in sequence to the Delta6-desaturase from the moss Physcomitrella patens. When these two cDNAs were expressed in Saccharomyces cerevisiae, both transgenic yeast cultures desaturated Delta9-unsaturated C16- and C18-fatty acids by inserting an additional Delta6cis-double bond. One of these transgenic yeast clones was also able to introduce a Delta6-triple bond into gamma-linolenic and stearidonic acid. This resulted in the formation of 9,12,15-(Z,Z,Z)-octadecatrien-6-ynoic acid, the main fatty acid found in C. pupureus. These results demonstrate that the Delta6-acetylenase from C. pupureus is a bifunctional enzyme, which can introduce a Delta6cis-double bond into 9,12,(15)-C18-polyenoic acids as well as converting a Delta6cis-double bond to a Delta6-triple bond.

  19. Atypical Biosynthetic Properties of a Δ12/ν+3 Desaturase from the Model Basidiomycete Phanerochaete chrysosporium▿ †

    PubMed Central

    Minto, Robert E.; Blacklock, Brenda J.; Younus, Hina; Pratt, Andrew C.

    2009-01-01

    The model white-rot basidiomycete Phanerochaete chrysosporium contains a single integral membrane Δ12-desaturase FAD2 related to the endoplasmic reticular plant FAD2 enzymes. The fungal fad2-like gene was cloned and distinguished itself from plant homologs by the presence of four introns and a significantly larger coding region. The coding sequence exhibits ca. 35% sequence identity to plant homologs, with the highest sequence conservation found in the putative catalytic and major structural domains. In vivo activity of the heterologously expressed enzyme favors C18 substrates with ν+3 regioselectivity, where the site of desaturation is three carbons carboxy-distal to the reference position of a preexisting double bond (ν). Linoleate accumulated to levels in excess of 12% of the total fatty acids upon heterologous expression of P. chrysosporium FAD2 in Saccharomyces cerevisiae. In contrast to the behavior of the plant FAD2 enzymes, this oleate desaturase does not 12-hydroxylate lipids and is the first example whose activity increases at higher temperatures (30°C versus 15°C). Thus, while maintaining the hallmark activity of the fatty acyl Δ12-desaturase family, the basidiomycete fad2 genes appear to have evolved substantially from an ancestral desaturase. PMID:19088315

  20. Isolation and Functional Characterisation of a fads2 in Rainbow Trout (Oncorhynchus mykiss) with Δ5 Desaturase Activity

    PubMed Central

    Abdul Hamid, Noor Khalidah; Carmona-Antoñanzas, Greta; Monroig, Óscar; Tocher, Douglas R.; Turchini, Giovanni M.; Donald, John A.

    2016-01-01

    Rainbow trout, Oncorhynchus mykiss, are intensively cultured globally. Understanding their requirement for long-chain polyunsaturated fatty acids (LC-PUFA) and the biochemistry of the enzymes and biosynthetic pathways required for fatty acid synthesis is important and highly relevant in current aquaculture. Most gnathostome vertebrates have two fatty acid desaturase (fads) genes with known functions in LC-PUFA biosynthesis and termed fads1 and fads2. However, teleost fish have exclusively fads2 genes. In rainbow trout, a fads2 cDNA had been previously cloned and found to encode an enzyme with Δ6 desaturase activity. In the present study, a second fads2 cDNA was cloned from the liver of rainbow trout and termed fads2b. The full-length mRNA contained 1578 nucleotides with an open reading frame of 1365 nucleotides that encoded a 454 amino acid protein with a predicted molecular weight of 52.48 kDa. The predicted Fads2b protein had the characteristic traits of the microsomal Fads family, including an N-terminal cytochrome b5 domain containing the heme-binding motif (HPPG), histidine boxes (HDXGH, HFQHH and QIEHH) and three transmembrane regions. The fads2b was expressed predominantly in the brain, liver, intestine and pyloric caeca. Expression of the fasd2b in yeast generated a protein that was found to specifically convert eicosatetraenoic acid (20:4n-3) to eicosapentaenoic acid (20:5n-3), and therefore functioned as a Δ5 desaturase. Therefore, rainbow trout have two fads2 genes that encode proteins with Δ5 and Δ6 desaturase activities, respectively, which enable this species to perform all the desaturation steps required for the biosynthesis of LC-PUFA from C18 precursors. PMID:26943160

  1. Regulation of Stearoyl Coenzyme A Desaturase 1 Gene Promoter in Bovine Mammary Cells.

    PubMed

    di Martino, O; Troiano, A; Addi, L; Guarino, A; Calabrò, S; Tudisco, R; Murru, N; Cutrignelli, M I; Infascelli, F; Calabrò, V

    2015-01-01

    Stearoyl-Coenzyme A desaturase 1 (SCD1) belongs to the fatty acid family of desaturases. In lactating ruminants, the SCD1 protein is highly expressed in the mammary gland and is relevant for the fatty acid composition of milk and dairy products. Bovine mammary epithelial cells (BME-UV1), cultured in vitro, have been proposed as a model to reproduce the biology of the mammary gland. The present study was designed to investigate the responsiveness of bovine SCD1 promoter to serum, insulin, oleic acid, and NFY transcription factor in BME-UV1 cells. A luciferase-based reporter assay was used to monitor the transcriptional activity of the SCD1 promoter region in BME-UV1 cells treated or not with insulin and/or oleic acid. The level of endogenous SCD1 mRNA was evaluated by Real time PCR. Insulin (20 ng/mL) induced a 2.0 to 2.5-fold increase of SCD1 promoter activity. Additionally, the effect of insulin was inhibited by oleic acid, serum components, and NFY enforced expression. Serum and NFY showed no synergistic or additive effect on SCD1 promoter activity suggesting that they repress SCD1 transcription through the same responsive element.

  2. [Cloning and functional characterization of phytoene desaturase in Andrographis paniculata].

    PubMed

    Shen, Qin-qin; Li, Li-xia; Zhan, Peng-lin; Wang, Qiang

    2015-10-01

    A full-length cDNA of phytoene desaturase (PDS) gene from Andrographis paniculata was obtained through RACE-PCR. The cDNA sequence consists of 2 224 bp with an intact ORF of 1 752 bp (GeneBank: KP982892), encoding a ploypeptide of 584 amino acids. Homology analysis showed that the deduced protein has extensive sequence similarities to PDS from other plants, and contains a conserved NAD ( H) -binding domain of plant dehydrase cofactor binding-domain in N-terminal. Phylogenetic analysis demonstrated that ApPDS was more related to PDS of Sesamum indicum and Pogostemon cablin. The semi-quantitative RT-PCR analysis revealed that ApPDS expressed in whole aboveground tissues with the highest expression in leaves. Virus induced gene silencing (VIGS) was performed to characterize the functional of ApPDS in planta. Significant photobleaching was not observed in infiltrated leaves, while the PDS gene has been down-regulated significantly at the yellowish area. To the best of our knowledge, this represents the first report of PDS gene cloning and functional characterization from A. paniculata, which lays the foundation for further investigation of new genes, especially that correlative to andrographolide biosynthetic pathway.

  3. Stearoyl CoA desaturase is required to produce active, lipid-modified Wnt proteins.

    PubMed

    Rios-Esteves, Jessica; Resh, Marilyn D

    2013-09-26

    Wnt proteins contain palmitoleic acid, an unusual lipid modification. Production of an active Wnt signal requires the acyltransferase Porcupine and depends on the attachment of palmitoleic acid to Wnt. The source of this monounsaturated fatty acid has not been identified, and it is not known how Porcupine recognizes its substrate and whether desaturation occurs before or after fatty acid transfer to Wnt. Here, we show that stearoyl desaturase (SCD) generates a monounsaturated fatty acid substrate that is then transferred by Porcupine to Wnt. Treatment of cells with SCD inhibitors blocked incorporation of palmitate analogs into Wnt3a and Wnt5a and reduced Wnt secretion as well as autocrine and paracrine Wnt signaling. The SCD inhibitor effects were rescued by exogenous addition of monounsaturated fatty acids. We propose that SCD is a key molecular player responsible for Wnt biogenesis and processing and that SCD inhibition provides an alternative mechanism for blocking Wnt pathway activation.

  4. Discovery of a disused desaturase gene from the pheromone gland of the moth Ascotis selenaria, which secretes an epoxyalkenyl sex pheromone.

    PubMed

    Fujii, Takeshi; Suzuki, Masataka G; Katsuma, Susumu; Ito, Katsuhiko; Rong, Yu; Matsumoto, Shogo; Ando, Tetsu; Ishikawa, Yukio

    2013-11-29

    Female Ascotis selenaria (Geometridae) moths use 3,4-epoxy-(Z,Z)-6,9-nonadecadiene, which is synthesized from linolenic acid, as the main component of their sex pheromone. While the use of dietary linolenic or linoleic fatty acid derivatives as sex pheromone components has been observed in moth species belonging to a few families including Geometridae, the majority of moths use derivatives of a common saturated fatty acid, palmitic acid, as their sex pheromone components. We attempted to gain insight into the differentiation of pheromone biosynthetic pathways in geometrids by analyzing the desaturase genes expressed in the pheromone gland of A. selenaria. We demonstrated that a Δ11-desaturase-like gene (Asdesat1) was specifically expressed in the pheromone gland of A. selenaria in spite of the absence of a desaturation step in the pheromone biosynthetic pathway in this species. Further analysis revealed that the presumed transmembrane domains were degenerated in Asdesat1. Phylogenetic analysis demonstrated that Asdesat1 anciently diverged from the lineage of Δ11-desaturases, which are currently widely used in the biosynthesis of sex pheromones by moths. These results suggest that an ancestral Δ11-desaturase became dysfunctional in A. selenaria after a shift in pheromone biosynthetic pathways.

  5. Characterization and regulation of the bovine stearoyl-CoA desaturase gene promoter

    SciTech Connect

    Keating, Aileen F.; Kennelly, John J.; Zhao Fengqi . E-mail: fzhao@uvm.edu

    2006-05-26

    The bovine stearoyl-CoA desaturase (Scd) gene plays an important role in the bovine mammary gland where substrates such as stearic and vaccenic acids are converted to oleic acid and conjugated linoleic acid (CLA), respectively. Up to 90% of the CLA in bovine milk is formed due to the action of this enzyme in the mammary gland. The areas of the bovine promoter of importance in regulating this key enzyme were examined and an area of 36 bp in length was identified as having a critical role in transcriptional activation and is designated the Scd transcriptional enhancer element (STE). Electrophoretic mobility shift assay detected three binding complexes on this area in Mac-T cell nuclear extracts. Treatment of cells with CLA caused a significant reduction in transcriptional activity, with this effect being mediated through the STE region. The bovine Scd gene promoter was up-regulated by insulin and down-regulated by oleic acid.

  6. Molecular breeding for introgression of fatty acid desaturase mutant alleles (ahFAD2A and ahFAD2B) enhances oil quality in high and low oil containing peanut genotypes.

    PubMed

    Janila, Pasupuleti; Pandey, Manish K; Shasidhar, Yaduru; Variath, Murali T; Sriswathi, Manda; Khera, Pawan; Manohar, Surendra S; Nagesh, Patne; Vishwakarma, Manish K; Mishra, Gyan P; Radhakrishnan, T; Manivannan, N; Dobariya, K L; Vasanthi, R P; Varshney, Rajeev K

    2016-01-01

    High oleate peanuts have two marketable benefits, health benefits to consumers and extended shelf life of peanut products. Two mutant alleles present on linkage group a09 (ahFAD2A) and b09 (ahFAD2B) control composition of three major fatty acids, oleic, linoleic and palmitic acids which together determine peanut oil quality. In conventional breeding, selection for fatty acid composition is delayed to advanced generations. However by using DNA markers, breeders can reject large number of plants in early generations and therefore can optimize time and resources. Here, two approaches of molecular breeding namely marker-assisted backcrossing (MABC) and marker-assisted selection (MAS) were employed to transfer two FAD2 mutant alleles from SunOleic 95R into the genetic background of ICGV 06110, ICGV 06142 and ICGV 06420. In summary, 82 MABC and 387 MAS derived introgression lines (ILs) were developed using DNA markers with elevated oleic acid varying from 62 to 83%. Oleic acid increased by 0.5-1.1 folds, with concomitant reduction of linoleic acid by 0.4-1.0 folds and palmitic acid by 0.1-0.6 folds among ILs compared to recurrent parents. Finally, high oleate ILs, 27 with high oil (53-58%), and 28 ILs with low oil content (42-50%) were selected that may be released for cultivation upon further evaluation.

  7. Role of stearoyl-CoA desaturase-1 in skin integrity and whole body energy balance.

    PubMed

    Sampath, Harini; Ntambi, James M

    2014-01-31

    The skin is the single largest organ in humans, serving as a major barrier to infection, water loss, and abrasion. The functional diversity of skin requires the synthesis of large amounts of lipids, such as triglycerides, wax esters, squalene, ceramides, free cholesterol, free fatty acids, and cholesterol and retinyl esters. Some of these lipids are used as cell membrane components, signaling molecules, and a source of energy. An important class of lipid metabolism enzymes expressed in skin is the Δ(9)-desaturases, which catalyze the synthesis in Δ(9)-monounsaturated lipids, primarily oleoyl-CoA (18:1n-9) and palmitoyl-CoA (16:1n-7), the major monounsaturated fatty acids in cutaneous lipids. Mice with a deletion of the Δ(9)-desaturase-1 isoform (SCD1) either globally (Scd1(-/-)) or specifically in the skin (skin-specific Scd1-knockout; SKO) present with marked changes in cutaneous lipids and skin integrity. Interestingly, these mice also exhibit increased whole body energy expenditure, protection against diet-induced adiposity, hepatic steatosis, and glucose intolerance. The increased energy expenditure in skin-specific Scd1-knockout (SKO) mice is a surprising phenotype, as it links cutaneous lipid homeostasis with whole body energy balance. This minireview summarizes the role of skin SCD1 in regulating skin integrity and whole body energy homeostasis and offers a discussion of potential pathways that may connect these seemingly disparate phenotypes.

  8. Temporal and tissue-specific regulation of a Brassica napus stearoyl-acyl carrier protein desaturase gene.

    PubMed Central

    Slocombe, S P; Piffanelli, P; Fairbairn, D; Bowra, S; Hatzopoulos, P; Tsiantis, M; Murphy, D J

    1994-01-01

    The nucleotide sequence of a Brassica napus stearoyl-acyl carrier protein desaturase gene (Bn10) is presented. This gene is one member of a family of four closely related genes expressed in oilseed rape. The expression of the promoter of this gene in transgenic tobacco was found to be temporally regulated in the developing seed tissues. However, the promoter was also particularly active in other oleogenic tissues such as the tapetum and pollen grains. This raises the interesting question of whether seed-expressed lipid synthesis genes are regulated by separate tissue-specific determinants or by a single factor common to all oleogenic tissues. Parts of the plants undergoing rapid development such as the components of immature flowers and seedlings also exhibited high levels of promoter activity. These tissues are likely to have an elevated requirement for membrane lipid synthesis. Stearoyl-acyl carrier protein desaturase transcript levels have previously been shown to be temporally regulated in the B. napus embryo (S.P. Slocombe, I. Cummins, R.P. Jarvis, D.J. Murphy [1992] Plant Mol Biol 20: 151-155). Evidence is presented demonstrating the induction of desaturase mRNA by abscisic acid in the embryo. PMID:8016261

  9. Primary structures of the precursor and mature forms of stearoyl-acyl carrier protein desaturase from safflower embryos and requirement of ferredoxin for enzyme activity.

    PubMed Central

    Thompson, G A; Scherer, D E; Foxall-Van Aken, S; Kenny, J W; Young, H L; Shintani, D K; Kridl, J C; Knauf, V C

    1991-01-01

    Stearoyl-acyl carrier protein (ACP) desaturase (EC 1.14.99.6) catalyzes the principal conversion of saturated fatty acids to unsaturated fatty acids in the synthesis of vegetable oils. Stearoyl-ACP desaturase was purified from developing embryos of safflower seed, and extensive amino acid sequence was determined. The amino acid sequence was used in conjunction with polymerase chain reactions to clone a full-length cDNA. The primary structure of the protein, as deduced from the nucleotide sequence of the cDNA, includes a 33-amino-acid transit peptide not found in the purified enzyme. Expression in Escherichia coli of a gene encoding the mature form of stearoyl-ACP desaturase did not result in an altered fatty acid composition. However, active enzyme was detected when assayed in vitro with added spinach ferredoxin. The lack of significant activity in vitro without added ferredoxin and the lack of observed change in fatty acid composition indicate that ferredoxin is a required cofactor for the enzyme and that E. coli ferredoxin functions poorly, if at all, as an electron donor for the plant enzyme. Images PMID:2006194

  10. Overexpression of the FAD3 desaturase gene in a mutant of Arabidopsis.

    PubMed Central

    Shah, S; Xin, Z; Browse, J

    1997-01-01

    A mutant of Arabidopsis contained increased levels of 18:3 fatty acids and correspondingly decreased levels of 18:2. The fatty acid phenotype was strongly expressed in root and seed tissues and this observation, together with other data, suggested that the mutation leads to increased activity of the endoplasmic reticulum 18:2 desaturase encoded by the FAD3 gene. Gel-blot analysis of RNA from wild-type and mutant plants established that FAD3 transcript levels were increased 80% in the mutant relative to the wild type. Genetic analysis demonstrated a linkage between the new mutation and the fad3 locus. Linkage of the mutation to fad3 raises the possibility that the lesion is an alteration to the promoter or another regulatory region of the FAD3 gene, which results in increased transcription. PMID:9276960

  11. Characterization of the fatty acyl elongase (elovl) gene family, and hepatic elovl and delta-6 fatty acyl desaturase transcript expression and fatty acid responses to diets containing camelina oil in Atlantic cod (Gadus morhua).

    PubMed

    Xue, Xi; Feng, Charles Y; Hixson, Stefanie M; Johnstone, Kim; Anderson, Derek M; Parrish, Christopher C; Rise, Matthew L

    2014-09-01

    For aquaculture to become sustainable, there is a need to substitute fish oil [FO, rich in ω3 long chain polyunsaturated fatty acids (LC-PUFA) such as 20:5ω3 (EPA) and 22:6ω3 (DHA)] in aquafeed with plant oils such as camelina oil [CO, rich in C18 PUFA such as 18:3ω3 (ALA) and 18:2ω6 (LNA)]. The LC-PUFA are essential components in fish diets for maintaining optimal health, physiology and growth. However, most marine fish including Atlantic cod are inefficient at producing LC-PUFA from shorter chain precursors. Since elovl genes encode enzymes that play key roles in fatty acid biosynthesis, we hypothesized that they may be involved in Atlantic cod responses to diets rich in 18:3ω3 and 18:2ω6. Ten members of the cod elovl gene family were characterized at the mRNA level. RT-PCR was used to study constitutive expression of elovl transcripts in fifteen tissues. Some transcripts (e.g. elovl5) were ubiquitously expressed, while others had tissue-specific expression (e.g. elovl4a in brain and eye). Cod fed a CO-containing diet (100% CO replacement of FO and including solvent-extracted fish meal) had significantly lower weight gain, with significant up-regulation of elovl5 and fadsd6 transcripts in the liver as shown by QPCR analysis, compared with cod on a FO control diet after a 13-week trial. Multivariate statistical analyses (SIMPER and PCA) indicated that high 18:3ω3 and/or low ω3 LC-PUFA levels in the liver were associated with the up-regulation of elovl5 and fadsd6, which are involved in LC-PUFA biosynthesis in cod.

  12. Effect of cod liver oil supplementation on the stearoyl-CoA desaturase index in obese children: a pilot study.

    PubMed

    Fujita, Yukihiko; Okada, Tomoo; Abe, Yuriko; Kazama, Minako; Saito, Emiko; Kuromori, Yuki; Iwata, Fujihiko; Hara, Mitsuhiko; Ayusawa, Mamoru; Izumi, Hiroyuki; Kitamura, Yohei; Shimizu, Takashi

    2015-01-01

    To investigate the effects of n-3 polyunsaturated fatty acids on stearoyl-CoA desaturase (SCD) activity, we treated 10 obese children (mean age: 12.9 years) with cod liver oil once daily for 12 weeks. The effects of cod liver oil supplementation on SCD activity, as estimated by the palmitoleate/palmitate ratio, depended on the docosahexaenoic acid (DHA) contents at baseline. Baseline DHA contents were negatively correlated with baseline SCD activity. After the treatment, baseline DHA contents were found to be significantly associated with the reduction of SCD activity. Cod liver oil supplementation may be a complementary treatment for obese children with low baseline contents of DHA.

  13. Cloning and functional expression of a cDNA encoding stearoyl-ACP Δ9-desaturase from the endosperm of coconut (Cocos nucifera L.).

    PubMed

    Gao, Lingchao; Sun, Ruhao; Liang, Yuanxue; Zhang, Mengdan; Zheng, Yusheng; Li, Dongdong

    2014-10-01

    Coconut (Cocos nucifera L.) is an economically tropical fruit tree with special fatty acid compositions. The stearoyl-acyl carrier protein (ACP) desaturase (SAD) plays a key role in the properties of the majority of cellular glycerolipids. In this paper, a full-length cDNA of a stearoyl-acyl carrier protein desaturase, designated CocoFAD, was isolated from cDNA library prepared from the endosperm of coconut (C. nucifera L.). An 1176 bp cDNA from overlapped PCR products containing ORF encoding a 391-amino acid (aa) protein was obtained. The coded protein was virtually identical and shared the homology to other Δ9-desaturase plant sequences (greater than 80% as similarity to that of Elaeis guineensis Jacq). The real-time fluorescent quantitative PCR result indicated that the yield of CocoFAD was the highest in the endosperm of 8-month-old coconut and leaf, and the yield was reduced to 50% of the highest level in the endosperm of 15-month-old coconut. The coding region showed heterologous expression in strain INVSc1 of yeast (Saccharomyces cerevisiae). GC-MS analysis showed that the levels of palmitoleic acid (16:1) and oleic acid (18:1) were improved significantly; meanwhile stearic acid (18:0) was reduced. These results indicated that the plastidial Δ9 desaturase from the endosperm of coconut was involved in the biosynthesis of hexadecenoic acid and octadecenoic acid, which was similar with other plants. These results may be valuable for understanding the mechanism of fatty acid metabolism and the genetic improvement of CocoFAD gene in palm plants in the future.

  14. Functional desaturase Fads1 (Δ5) and Fads2 (Δ6) orthologues evolved before the origin of jawed vertebrates.

    PubMed

    Castro, Luís Filipe Costa; Monroig, Óscar; Leaver, Michael J; Wilson, Jonathan; Cunha, Isabel; Tocher, Douglas R

    2012-01-01

    Long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are essential components of biomembranes, particularly in neural tissues. Endogenous synthesis of ARA, EPA and DHA occurs from precursor dietary essential fatty acids such as linoleic and α-linolenic acid through elongation and Δ5 and Δ6 desaturations. With respect to desaturation activities some noteworthy differences have been noted in vertebrate classes. In mammals, the Δ5 activity is allocated to the Fads1 gene, while Fads2 is a Δ6 desaturase. In contrast, teleosts show distinct combinations of desaturase activities (e.g. bifunctional or separate Δ5 and Δ6 desaturases) apparently allocated to Fads2-type genes. To determine the timing of Fads1-Δ5 and Fads2-Δ6 evolution in vertebrates we used a combination of comparative and functional genomics with the analysis of key phylogenetic species. Our data show that Fads1 and Fads2 genes with Δ5 and Δ6 activities respectively, evolved before gnathostome radiation, since the catshark Scyliorhinus canicula has functional orthologues of both gene families. Consequently, the loss of Fads1 in teleosts is a secondary episode, while the existence of Δ5 activities in the same group most likely occurred through independent mutations into Fads2 type genes. Unexpectedly, we also establish that events of Fads1 gene expansion have taken place in birds and reptiles. Finally, a fourth Fads gene (Fads4) was found with an exclusive occurrence in mammalian genomes. Our findings enlighten the history of a crucially important gene family in vertebrate fatty acid metabolism and physiology and provide an explanation of how observed lineage-specific gene duplications, losses and diversifications might be linked to habitat-specific food web structures in different environments and over geological timescales.

  15. Evolution of Moth Sex Pheromone Desaturases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moth sex pheromone communication has evolved to make use of complex blends of relatively simple long-chain fatty acid precursors. Species specificity is derived from the unique stereochemistry of double bonds introduced into exact locations along the hydrocarbon backbone of fatty acids, which are r...

  16. Analysis of an essential carotenogenic enzyme: ζ-carotene desaturase from unicellular Alga Dunaliella salina.

    PubMed

    Ye, Zhi-Wei; Jiang, Jian-Guo

    2010-11-10

    The green alga Dunaliella has become a valuable model organism for understanding the interesting mechanism of massive carotenoid accumulation. Previously, DNA sequences of several carotenogenic enzymes were obtained from Dunaliella. In this study, the cDNA of zds was isolated from Dunaliella salina using a polymerase chain reaction approach. The full-length cDNA sequence was 2178 base pairs (bp) containing a 1731 bp putative open reading frame which coded a 576 amino acid deduced polypeptide whose molecular weight was 63.9 kDa computationally. A complete homologous search displayed that the nucleotide and putative protein sequence have sequence identities of 69% and 66% with those of green alga Chlamydomonas reinhardtii, respectively. It was predicted that this ζ-carotene desaturase (Zds) may be located in the chloroplast of D. salina. Phylogenetic analysis demonstrated that the D. salina Zds had a closer relationship with the Zds of algae and higher plants than with those of other species.

  17. Genes encoding Δ(8)-sphingolipid desaturase from various plants: identification, biochemical functions, and evolution.

    PubMed

    Li, Shu-Fen; Zhang, Guo-Jun; Zhang, Xue-Jin; Yuan, Jin-Hong; Deng, Chuan-Liang; Hu, Zan-Min; Gao, Wu-Jun

    2016-09-01

    ∆(8)-sphingolipid desaturase catalyzes the C8 desaturation of a long chain base, which is the characteristic structure of various complex sphingolipids. The genes of 20 ∆(8)-sphingolipid desaturases from 12 plants were identified and functionally detected by using Saccharomyces cerevisiae system to elucidate the relationship between the biochemical function and evolution of this enzyme. Results showed that the 20 genes all can encode a functional ∆(8)-sphingolipid desaturase, which catalyzes different ratios of two products, namely, 8(Z) and 8(E)-C18-phytosphingenine. The coded enzymes could be divided into two groups on the basis of biochemical functions: ∆(8)-sphingolipid desaturase with a preference for an E-isomer product and ∆(8)-sphingolipid desaturase with a preference for a Z-isomer product. The conversion rate of the latter was generally lower than that of the former. Phylogenetic analysis revealed that the 20 desaturases could also be clustered into two groups, and this grouping is consistent with that of the biochemical functions. Thus, the biochemical function of ∆(8)-sphingolipid desaturase is correlated with its evolution. The two groups of ∆(8)-sphingolipid desaturases could arise from distinct ancestors in higher plants. However, they might have initially evolved from ∆(8)-sphingolipid desaturases in lower organisms, such as yeasts, which can produce E-isomer products only. Furthermore, almost all of the transgenic yeasts harboring ∆(8)-sphingolipid desaturase genes exhibit an improvement in aluminum tolerance. Our study provided new insights into the biochemical function and evolution of ∆(8)-sphingolipid desaturases in plants.

  18. Genomic structures and characterization of the 5'-flanking regions of acyl carrier protein and Delta4-palmitoyl-ACP desaturase genes from Coriandrum sativum.

    PubMed

    Kim, Mi Jung; Shin, Jeong Sheop; Kim, Jeong-Kook; Suh, Mi Chung

    2005-09-25

    The seed-specific or seed-predominant promoters of acyl carrier protein (Cs-ACP1) and Delta4-palmitoyl-acyl carrier protein desaturase (Cs-4PAD) genes, which are involved in the biosynthesis of petroselinic acid, were isolated from coriander (Coriandrum sativum) and analyzed in coriander endosperms and transgenic Arabidopsis. The expression of Cs-ACP1 and Cs-4PAD genes was coordinately regulated during seed development.

  19. Discrete roles of a microsomal linoleate desaturase gene in olive identified by spatiotemporal transcriptional analysis.

    PubMed

    Banilas, Georgios; Nikiforiadis, Alkis; Makariti, Ifigenia; Moressis, Anastassios; Hatzopoulos, Polydefkis

    2007-04-01

    The relative abundance of alpha-linolenic (alpha-LeA) compared with linoleic acid is associated with the developmental stage and the plant species and is proposed to have important physiological effects on both vegetative and reproductive plant development. The enzymes responsible for catalyzing the conversion of linoleic acid to alpha-LeA, the omega-3 fatty acid desaturases (FADs), are localized in the plastid or the endoplasmic reticulum (ER). Here we present the isolation of an ER-type omega-3 FAD gene (OeFAD3) from olive (Olea europaea L.). Expression patterns of OeFAD3 in different seed tissues and mesocarps during olive fruit development showed that its contribution to olive oil biosynthesis and modification is minimal. Regulation of OeFAD3 differed from that of its plastidial counterpart, being preferentially expressed in proliferating tissues, in concert with the active membrane biogenesis required for cell division. Trienoic acid-deficient Arabidopsis mutants are male sterile, because alpha-LeA-derived jasmonic acid (JA) is required for pollen development. However, the upregulation of OeFAD3 in different pistil tissues, particularly in vascular bundles and ovaries, rather than in anthers, implies a critical role of alpha-LeA in female gametophyte development in olive, corroborating results from JA-defective tomato mutants that are female sterile but not male sterile.

  20. Cloning of phytoene desaturase and expression analysis of carotenogenic genes in persimmon (Diospyros kaki L.) fruits.

    PubMed

    Zhao, Daqiu; Zhou, Chunhua; Kong, Fen; Tao, Jun

    2011-08-01

    Persimmon is a commercially important fruit crop, and the fruit is rich in different kinds of bioactive compounds, among which carotenoids contribute significantly to its color and nutritional value. In this study, the cDNA of phytoene desaturase gene (PDS) was isolated by rapid amplification of cDNA ends (RACE) technique. Sequence analysis indicated that the full-length cDNA of PDS was 2064 bp, encoding 586 amino acids and containing one open reading frame (ORF) of 1761 bp. Homology analysis showed that DkPDS, which had been submitted in GenBank with accession number GU112527, shared high similarities of 80-86% with PDS cloned from other plants. Prediction of deduced proteins showed that there was no signal peptide and transmembrane topological structure in DkPDS. It was a hydrophilic and stable protein, and located in chloroplast. To examine the specific expression patterns of carotenogenic genes we had cloned from persimmon, including phytoene synthase (DkPSY), DkPDS, ζ-carotene desaturase (DkZDS), lycopene β-cyclase (DkLCYB) and β-carotene hydroxylase (DkBCH), real-time quantitative PCR (Q-PCR) was performed in flesh at five different developmental stages. The results revealed that the expression levels of DkPSY, DkPDS and DkZDS gradually increased. Nevertheless, the expression level of DkLCYB was very low and maintained relatively stable. The expression level of DkBCH was also at a low level from stage 1 to 4, and then reached the maximum at stage 5. In addition, the expression level of DkZDS was higher than that of other genes. Carotenoid detection demonstrated that both β-cryptoxanthin and total carotenoids increased with fruit development, and zeaxanthin had little change, but with a sudden increase in final stage.

  1. Identification and characterization of hamster stearoyl-CoA desaturase isoforms.

    PubMed

    Wang, Jian; Yu, Lan; Wang, He; Gao, Yunling; Schrementi, James P; Porter, Regina K; Yurek, David A; Kuo, Mingshang; Suen, Chen-Shian; Cao, Guoqing; Bean, James S; Kauffman, Raymond F; Qian, Yuewei

    2008-03-01

    Stearoyl-CoA desaturase (SCD) catalyzes the formation of monounsaturated fatty acids from saturated fatty acids. It plays a key role in lipid metabolism and energy expenditure in mammals. In mice, four SCD isoforms (SCD1-4) have been identified. Here we report the identification of cDNA sequences corresponding to SCD1, SCD2 and SCD3 of golden hamster. The deduced amino acid sequences of these hamster SCD (hmSCD) isoforms display a high degree of homologies to their mouse counterparts (mouse SCD). Polyclonal antibodies specific to rodent SCDs detected proteins of predicted size in the human embryonic kidney 293 cells transfected with hmSCD cDNAs. Microsome fractions prepared from these cells also displayed increased SCD activity versus cells transfected with vector alone. Real-time reverse transcription-polymerase chain reaction analysis revealed the highest expression of hmSCD1 in liver and adipose tissue, while the highest hmSCD2 expression was detected in the brain. Very low levels of hmSCD3 mRNA can be detected in the tissues tested. This report is the first description of three SCD isoforms in the hamster and will provide useful tools in the further study of fatty acids metabolism in this species.

  2. Characterization of an oleate 12-desaturase from Physaria fendleri and identification of 5'UTR introns in divergent FAD2 family genes.

    PubMed

    Lozinsky, Sharla; Yang, Hui; Forseille, Li; Cook, Gillian R; Ramirez-Erosa, Irving; Smith, Mark A

    2014-02-01

    Mining of an EST sequence collection representing genes expressed during seed development in Physaria fendleri identified abundant sequences encoding apparent homologues of the Arabidopsis oleate 12-desaturase (AtFAD2 At3g12120). Of the 62 sequenced clones, 59 were identified as encoding the previously characterized bifunctional oleate 12-hydroxylase/desaturase (LFAH12/PfFAH12). The remaining 3 clones encoded a second FAD2 homologue. Isolation of a full length ORF and heterologous expression in yeast revealed that this sequence, designated PfFAD2, is the first full length sequence from any Physaria species that encodes an oleate 12-desaturase. PfFAD2 was expressed in both leaf and developing seed with activity on palmitate (16:1(Δ9)) and oleate (18:1(Δ9)). Sequence comparison revealed that PfFAD2 shares 93% amino acid identity with Arabidopsis FAD2 and only 84% identity with PfFAH12. By comparison of EST and genomic sequences it was revealed that the PfFAD2 gene encodes a transcript with a single intron of 1120 bp in the 5'-untranslated region (5'UTR). A short intron, 81 bp in length, was also discovered in the 5'UTR of the PfFAH12 gene, 16 bp upstream of the translation initiation codon. In silico examination of FAD2 like genes from the genome of castor (Ricinus communis) identified putative 5'UTR introns in genes encoding the castor oleate 12-desaturase (RcFAD2) and oleate 12-hydroxylase (CFAH12). By sequencing of genomic DNA the presence of single 5'UTR introns in each gene, and the size of these introns, was confirmed. These findings suggest that 5'UTR introns may be a characteristic feature of FAD2 genes and also of divergent FAD2 genes encoding fatty acid modifying enzymes, and that the selection pressure maintaining these introns is very different.

  3. Acyl-lipid desaturase 1 primes cold acclimation response in Arabidopsis.

    PubMed

    Chen, Mingjie; Thelen, Jay J

    2016-09-01

    Membrane fluidity change has long been suggested as the primary mechanism by which, plants adapt to cold stress, but the underlying molecular mechanisms are not completely established. In this study, we found that a knockout of acyl-lipid/CoA desaturase 1 gene (ADS1; EC 1.14.99) enhances freezing tolerance after cold acclimation (CA). Fatty acid composition analysis demonstrated that 18:1 content in ads1 mutant plants was 20% lower than in wild-type (WT) grown at 23°C. Lipidomics revealed that 34C-species of monogalactosyl diacylglycerol (MGDG) content in ads1 mutants were 3.3-14.9% lower than in WT. Lipid positional analysis identified 10% lower 18:1 fatty acid content at the sn-2 position of MGDG. The cytosolic calcium content in ads1 mutant plants was also approximately two-times higher than that of WT in response to cold shock. Each of these biochemical differences between WT and ads1 mutant disappeared after CA. Subcellular localization of C- and N-terminal enhanced-fluorescence-fusion proteins indicated that ADS1 localized exclusively to chloroplasts. These observations suggest that ADS1-mediated alteration of chloroplast membrane fluidity is required to prime a CA response, and is the upstream event of cytosolic calcium signaling.

  4. Hydrostatic pressure decreases membrane fluidity and lipid desaturase expression in chondrocyte progenitor cells.

    PubMed

    Montagne, Kevin; Uchiyama, Hiroki; Furukawa, Katsuko S; Ushida, Takashi

    2014-01-22

    Membrane biomechanical properties are critical in modulating nutrient and metabolite exchange as well as signal transduction. Biological membranes are predominantly composed of lipids, cholesterol and proteins, and their fluidity is tightly regulated by cholesterol and lipid desaturases. To determine whether such membrane fluidity regulation occurred in mammalian cells under pressure, we investigated the effects of pressure on membrane lipid order of mouse chondrogenic ATDC5 cells and desaturase gene expression. Hydrostatic pressure linearly increased membrane lipid packing and simultaneously repressed lipid desaturase gene expression. We also showed that cholesterol mimicked and cholesterol depletion reversed those effects, suggesting that desaturase gene expression was controlled by the membrane physical state itself. This study demonstrates a new effect of hydrostatic pressure on mammalian cells and may help to identify the molecular mechanisms involved in hydrostatic pressure sensing in chondrocytes.

  5. Stereochemistry of 10-sulfoxidation catalyzed by a soluble delta9 desaturase

    SciTech Connect

    Tremblay, A.E.; Shanklin, J.; Tan, N.; Whittle, E.; Hodgson, D. J.; Dawson, B.; Buist, P. H.

    2010-03-21

    The stereochemistry of castor stearoyl-ACP 9 desaturase-mediated 10-sulfoxidation has been determined. This was accomplished by 19F NMR analysis of a fluorine-tagged product, 18-fluoro-10-thiastearoyl ACP S-oxide, in combination with a chiral solvating agent, (R)-AMA. Sulfoxidation proceeds with the same stereoselectivity as hydrogen removal from the parent stearoyl substrate. These data validate the use of thia probes to determine the stereochemistry and cryptoregiochemistry of desaturase-mediated oxidations.

  6. Evolution of the insect desaturase gene family with an emphasis on social Hymenoptera.

    PubMed

    Helmkampf, Martin; Cash, Elizabeth; Gadau, Jürgen

    2015-02-01

    Desaturase genes are essential for biological processes, including lipid metabolism, cell signaling, and membrane fluidity regulation. Insect desaturases are particularly interesting for their role in chemical communication, and potential contribution to speciation, symbioses, and sociality. Here, we describe the acyl-CoA desaturase gene families of 15 insects, with a focus on social Hymenoptera. Phylogenetic reconstruction revealed that the insect desaturases represent an ancient gene family characterized by eight subfamilies that differ strongly in their degree of conservation and frequency of gene gain and loss. Analyses of genomic organization showed that five of these subfamilies are represented in a highly microsyntenic region conserved across holometabolous insect taxa, indicating an ancestral expansion during early insect evolution. In three subfamilies, ants exhibit particularly large expansions of genes. Despite these expansions, however, selection analyses showed that desaturase genes in all insect lineages are predominantly undergoing strong purifying selection. Finally, for three expanded subfamilies, we show that ants exhibit variation in gene expression between species, and more importantly, between sexes and castes within species. This suggests functional differentiation of these genes and a role in the regulation of reproductive division of labor in ants. The dynamic pattern of gene gain and loss of acyl-CoA desaturases in ants may reflect changes in response to ecological diversification and an increased demand for chemical signal variability. This may provide an example of how gene family expansions can contribute to lineage-specific adaptations through structural and regulatory changes acting in concert to produce new adaptive phenotypes.

  7. Cloning and tissue distribution of a fatty acyl Δ6-desaturase-like gene and effects of dietary lipid levels on its expression in the hepatopancreas of Chinese mitten crab (Eriocheir sinensis).

    PubMed

    Yang, Zhigang; Guo, Zihao; Ji, Lianyuan; Zeng, Qitao; Wang, Yao; Yang, Xiaozhen; Cheng, Yongxu

    2013-06-01

    Fatty acyl Δ6-desaturase is the rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acids (HUFAs) in vertebrates. In this report, a fatty acyl Δ6-desaturase-like cDNA was cloned from the hepatopancreas of Eriocheir sinensis (Chinese mitten crab) and characterized by performing rapid-amplification of cDNA ends. The 2278-bp long full-length cDNA encodes a polypeptide with 442 amino acids. Gene expression analysis via real-time quantitative polymerase chain reaction revealed that the fatty acyl Δ6-desaturase-like transcripts are widely distributed in various tissues, with high expression levels in the hepatopancreas and cranial ganglia. This study focuses on the nutritional regulation of genes involved in the HUFA biosynthetic pathway in Chinese mitten crab. A feeding trial was performed whereby crablets were fed for 238 d with four different diets: control diet without oil lipids (added with 3% basic lipid of the fundamental diets); fish oil diet (FO; added with 3% of the fundamental diets); soybean oil diet (SO; added with 3% of the fundamental diets); and FO/SO diet (1:1; added with 3% of the fundamental diets). The hepatopancreas of crabs sampled at 168 d and 238 d to determine the effects on fatty acyl Δ6-desaturase-like mRNA expression. The results show that the expression of fatty acyl Δ6-desaturase-like is higher in the hepatopancreas of crabs fed with SO diet than those fed with FO diet. Furthermore, gene expression increased by 2.45-fold in the hepatopancreas of crabs fed with SO after 238 d than those fed after 168 d but remained steady for those fed with FO after 238 d.

  8. Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants

    DOEpatents

    Ohlrogge, John B.; Cahoon, Edgar B.; Shanklin, John; Somerville, Christopher R.

    1995-01-01

    The present invention relates to a process for producing lipids containing the fatty acid petroselinic acid in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a .omega.12 desaturase from another species which does normally accumulate petroselinic acid.

  9. Method for production of petroselinic acid and OMEGA12 hexadecanoic acid in transgenic plants

    DOEpatents

    Ohlrogge, J.B.; Cahoon, E.B.; Shanklin, J.; Somerville, C.R.

    1995-07-04

    The present invention relates to a process for producing lipids containing the fatty acid, petroselinic acid, in plants. The production of petroselinic acid is accomplished by genetically transforming plants which do not normally accumulate petroselinic acid with a gene for a {omega}12 desaturase from another species which does normally accumulate petroselinic acid. 19 figs.

  10. Expression of a fungal sterol desaturase improves tomato drought tolerance, pathogen resistance and nutritional quality

    PubMed Central

    Kamthan, Ayushi; Kamthan, Mohan; Azam, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

    2012-01-01

    Crop genetic engineering mostly aims at improving environmental stress (biotic and abiotic) tolerance as well as nutritional quality. Empowering a single crop with multiple traits is highly demanding and requires manipulation of more than one gene. However, we report improved drought tolerance and fungal resistance along with the increased iron and polyunsaturated fatty acid content in tomato by expressing a single gene encoding C-5 sterol desaturase (FvC5SD) from an edible fungus Flammulina velutipes. FvC5SD is an iron binding protein involved in ergosterol biosynthesis. Morphological and biochemical analyses indicated ≈23% more epicuticular wax deposition in leaves of transgenic plants that provides an effective waterproof barrier resulting in improved protection from drought and infection by phytopathogenic fungus Sclerotinia sclerotiorum. Furthermore, the transgenic fruits have improved nutritional value attributed to enhanced level of beneficial PUFA and 2-3 fold increase in total iron content. This strategy can be extended to other economically important crops. PMID:23230516

  11. Stearoyl-acyl carrier protein desaturase gene from the oleaginous microalga Chlorella zofingiensis: cloning, characterization and transcriptional analysis.

    PubMed

    Liu, Jin; Sun, Zheng; Zhong, Yujuan; Huang, Junchao; Hu, Qiang; Chen, Feng

    2012-12-01

    The green alga Chlorella zofingiensis can accumulate high level of oleic acid (OA, C18:1△(9)) rich oils in response to stress conditions. To understand the regulation of biosynthesis of fatty acid in particular OA at the molecular level, we cloned and characterized the stearoyl acyl carrier protein (ACP) desaturase (SAD) responsible for OA formation through desaturation of stearic acid (C18:0) from C. zofingiensis. Southern blot indicated that the C. zofingiensis genome contained a single copy of SAD, from which the deduced amino acid sequence shared high identity to the corresponding homologs from other microalgae and higher plants. The desaturation activity of SAD was demonstrated in vitro using C18:0-ACP as a substrate. Stress conditions such as high light (HL), nitrogen deficiency (N(-)), or combination of HL and N(-) (HL + N(-)) drastically up-regulated the transcripts of biotin carboxylase (BC, a subunit of ACCase) and SAD, and therefore induced considerably the cellular accumulation of total fatty acids including OA. Glucose (50 mM) gave rise to the similar up-regulation of the two genes and induction of fatty acid accumulation. The accumulation of intracellular reactive oxygen species was found to be associated with the up-regulation of genes. This is the first report of characterization of Chlorella-derived SAD and the results may contribute to understanding of the mechanisms involved in fatty acid/lipid biosynthesis in microalgae.

  12. Preliminary safety assessment of a membrane-bound delta 9 desaturase candidate protein for transgenic oilseed crops.

    PubMed

    Madduri, Krishna M; Schafer, Barry W; Hasler, James M; Lin, Gaofeng; Foster, Mendy L; Embrey, Shawna K; Sastry-Dent, Lakshmi; Song, Ping; Larrinua, Ignacio M; Gachotte, Daniel J; Herman, Rod A

    2012-10-01

    A gene encoding delta 9 desaturase (D9DS), an integral membrane protein, is being considered for incorporation into oilseed crops to reduce saturated fatty acids and thus improve human nutritional value. Typically, a safety assessment for transgenic crops involves purifying heterologously produced transgenic proteins in an active form for use in safety studies. Membrane-bound proteins have been very difficult to isolate in an active form due to their inherent physicochemical properties. Described here are methods used to derive enriched preparations of the active D9DS protein for use in early stage safety studies. Results of these studies, in combination with bioinformatic results and knowledge of the mode of action of the protein, along with a history of safe consumption of related proteins, provides a weight of evidence supporting the safety of the D9DS protein in food and feed.

  13. Variants in CPT1A, FADS1, and FADS2 are Associated with Higher Levels of Estimated Plasma and Erythrocyte Delta-5 Desaturases in Alaskan Eskimos

    PubMed Central

    Voruganti, V. Saroja; Higgins, Paul B.; Ebbesson, Sven O. E.; Kennish, John; Göring, Harald H. H.; Haack, Karin; Laston, Sandra; Drigalenko, Eugene; Wenger, Charlotte R.; Harris, William S.; Fabsitz, Richard R.; Devereux, Richard B.; MacCluer, Jean W.; Curran, Joanne E.; Carless, Melanie A.; Johnson, Matthew P.; Moses, Eric K.; Blangero, John; Umans, Jason G.; Howard, Barbara V.; Cole, Shelley A.; Comuzzie, Anthony Gean

    2012-01-01

    The delta-5 and delta-6 desaturases (D5D and D6D), encoded by fatty acid desaturase 1 (FADS1) and 2 (FADS2) genes, respectively, are rate-limiting enzymes in the metabolism of ω-3 and ω-6 fatty acids. The objective of this study was to identify genes influencing variation in estimated D5D and D6D activities in plasma and erythrocytes in Alaskan Eskimos (n = 761) participating in the genetics of coronary artery disease in Alaska Natives (GOCADAN) study. Desaturase activity was estimated by product: precursor ratio of polyunsaturated fatty acids. We found evidence of linkage for estimated erythrocyte D5D (eD5D) on chromosome 11q12-q13 (logarithm of odds score = 3.5). The confidence interval contains candidate genes FADS1, FADS2, 7-dehydrocholesterol reductase (DHCR7), and carnitine palmitoyl transferase 1A, liver (CPT1A). Measured genotype analysis found association between CPT1A, FADS1, and FADS2 single-nucleotide polymorphisms (SNPs) and estimated eD5D activity (p-values between 10−28 and 10−5). A Bayesian quantitative trait nucleotide analysis showed that rs3019594 in CPT1A, rs174541 in FADS1, and rs174568 in FADS2 had posterior probabilities > 0.8, thereby demonstrating significant statistical support for a functional effect on eD5D activity. Highly significant associations of FADS1, FADS2, and CPT1A transcripts with their respective SNPs (p-values between 10−75 and 10−7) in Mexican Americans of the San Antonio Family Heart Study corroborated our results. These findings strongly suggest a functional role for FADS1, FADS2, and CPT1A SNPs in the variation in eD5D activity. PMID:22701466

  14. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  15. The stearoyl-acyl-carrier-protein desaturase promoter (Des) from oil palm confers fruit-specific GUS expression in transgenic tomato.

    PubMed

    Saed Taha, Rima; Ismail, Ismanizan; Zainal, Zamri; Abdullah, Siti Nor Akmar

    2012-09-01

    The stearoyl-acyl-carrier-protein (ACP) desaturase is a plastid-localized enzyme that catalyzes the conversion of stearoyl-ACP to oleoyl-ACP and plays an important role in the determination of the properties of the majority of cellular glycerolipids. Functional characterization of the fatty acid desaturase genes and their specific promoters is a prerequisite for altering the composition of unsaturated fatty acids of palm oil by genetic engineering. In this paper, the specificity and strength of the oil palm stearoyl-ACP desaturase gene promoter (Des) was evaluated in transgenic tomato plants. Transcriptional fusions between 5' deletions of the Des promoter (Des1-4) and the β-glucuronidase (GUS) reporter gene were generated and their expression analyzed in different tissues of stably transformed tomato plants. Histochemical analysis of the Des promoter deletion series revealed that GUS gene expression was confined to the tomato fruits. No expression was detected in vegetative tissues of the transgenic plants. The highest levels of GUS activity was observed in different tissues of ripe red fruits (vascular tissue, septa, endocarp, mesocarp and columella) and in seeds, which harbored the promoter region located between -590 and +10. A comparison of the promoter-deletion constructs showed that the Des4 promoter deletion (314bp) produced a markedly low level of GUS expression in fruits and seeds. Fluorometric analysis of the GUS activity revealed a 4-fold increase in the activity of the full-length Des promoter compared to the CaMV35S promoter. RNA-hybridization analyses provided additional evidence of increased GUS expression in fruits driven by a Des fragment. Taken together, these results demonstrate the potential of the Des promoter as a tool for the genetic engineering of oil palms and other species, including dicots, in improving the quality and nutritional value of the fruits.

  16. Characterization of a higher plant herbicide-resistant phytoene desaturase and its use as a selectable marker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three natural somatic mutations at codon 304 of the phytoene desaturase gene (pds) of Hydrilla verticillata ( L. f. Royle) have been reported to provide resistance to the herbicide fluridone. We substituted the arginine 304 present in the wild-type H. verticillata phytoene desaturase (PDS) with all...

  17. X-ray structure of putative acyl-ACP desaturase DesA2 from Mycobacterium tuberculosis H37Rv

    SciTech Connect

    Dyer, David H.; Lyle, Karen S.; Rayment, Ivan; Fox, Brian G.

    2010-07-13

    Genome sequencing showed that two proteins in Mycobacterium tuberculosis H37Rv contain the metal binding motif (D/E)X{sub 2}HX{sub {approx}100}(D/E)X{sub 2}H characteristic of the soluble diiron enzyme superfamily. These putative acyl-ACP desaturase genes desA1 and desA2 were cloned from genomic DNA and expressed in Escherichia coli BL21(DE3). DesA1 was found to be insoluble, but in contrast, DesA2 was a soluble protein amenable to biophysical characterization. Here, we report the 2.0 {angstrom} resolution X-ray structure of DesA2 determined by multiple anomalous dispersion (MAD) phasing from a Se-met derivative and refinement against diffraction data obtained on the native protein. The X-ray structure shows that DesA2 is a homodimeric protein with a four-helix bundle core flanked by five additional helices that overlay with 192 structurally equivalent amino acids in the structure of stearoyl-ACP {Delta}9 desaturase from castor plant with an rms difference 1.42 {angstrom}. In the DesA2 crystals, one metal (likely Mn from the crystallization buffer) was bound in high occupancy at the B-site of the conserved metal binding motif, while the A-site was not occupied by a metal ion. Instead, the amino group of Lys-76 occupied this position. The relationships between DesA2 and known diiron enzymes are discussed.

  18. Molecular cloning and expression in photosynthetic bacteria of a soybean cDNA coding for phytoene desaturase, an enzyme of the carotenoid biosynthesis pathway.

    PubMed Central

    Bartley, G E; Viitanen, P V; Pecker, I; Chamovitz, D; Hirschberg, J; Scolnik, P A

    1991-01-01

    Carotenoids are orange, yellow, or red photo-protective pigments present in all plastids. The first carotenoid of the pathway is phytoene, a colorless compound that is converted into colored carotenoids through a series of desaturation reactions. Genes coding for carotenoid desaturases have been cloned from microbes but not from plants. We report the cloning of a cDNA for pds1, a soybean (Glycine max) gene that, based on a complementation assay using the photosynthetic bacterium Rhodobacter capsulatus, codes for an enzyme that catalyzes the two desaturation reactions that convert phytoene into zeta-carotene, a yellow carotenoid. The 2281-base-pair cDNA clone analyzed contains an open reading frame with the capacity to code for a 572-residue protein of predicted Mr 63,851. Alignment of the deduced Pds1 peptide sequence with the sequences of fungal and bacterial carotenoid desaturases revealed conservation of several amino acid residues, including a dinucleotide-binding motif that could mediate binding to FAD. The Pds1 protein is synthesized in vitro as a precursor that, upon import into isolated chloroplasts, is processed to a smaller mature form. Hybridization of the pds1 cDNA to genomic blots indicated that this gene is a member of a low-copy-number gene family. One of these loci was genetically mapped using restriction fragment length polymorphisms between Glycine max and Glycine soja. We conclude that pds1 is a nuclear gene encoding a phytoene desaturase enzyme that, as its microbial counterparts, contains sequence motifs characteristic of flavoproteins. Images PMID:1862081

  19. Stearoyl-CoA desaturase-1 is a key factor for lung cancer-initiating cells

    PubMed Central

    Noto, A; Raffa, S; De Vitis, C; Roscilli, G; Malpicci, D; Coluccia, P; Di Napoli, A; Ricci, A; Giovagnoli, M R; Aurisicchio, L; Torrisi, M R; Ciliberto, G; Mancini, R

    2013-01-01

    In recent years, studies of cancer development and recurrence have been influenced by the cancer stem cells (CSCs)/cancer-initiating cells (CICs) hypothesis. According to this, cancer is sustained by highly positioned, chemoresistant cells with extensive capacity of self renewal, which are responsible for disease relapse after chemotherapy. Growth of cancer cells as three-dimensional non-adherent spheroids is regarded as a useful methodology to enrich for cells endowed with CSC-like features. We have recently reported that cell cultures derived from malignant pleural effusions (MPEs) of patients affected by adenocarcinoma of the lung are able to efficiently form spheroids in non-adherent conditions supplemented with growth factors. By expression profiling, we were able to identify a set of genes whose expression is significantly upregulated in lung tumor spheroids versus adherent cultures. One of the most strongly upregulated gene was stearoyl-CoA desaturase (SCD1), the main enzyme responsible for the conversion of saturated into monounsaturated fatty acids. In the present study, we show both by RNA interference and through the use of a small molecule inhibitor that SCD1 is required for lung cancer spheroids propagation both in stable cell lines and in MPE-derived primary tumor cultures. Morphological examination and image analysis of the tumor spheroids formed in the presence of SCD1 inhibitors showed a different pattern of growth characterized by irregular cell aggregates. Electron microscopy revealed that the treated spheroids displayed several features of cellular damage and immunofluorescence analysis on optical serial sections showed apoptotic cells positive for the M30 marker, most of them positive also for the stemness marker ALDH1A1, thus suggesting that the SCD1 inhibitor is selectively killing cells with stem-like properties. Furthermore, SCD1-inhibited lung cancer cells were strongly impaired in their in vivo tumorigenicity and ALDH1A1 expression. These

  20. Phytoene desaturase is present in a large protein complex in the plastid membrane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoene desaturase (PDS, EC 1.14.99.-) represents one of the key enzymes in the carotenoid biosynthetic pathway and is present in nearly all types of plastids in plants. To further characterize PDS, we isolated the PDS cDNA from cauliflower (BoPDS) and confirmed its function by heterologous express...

  1. Stearoyl-CoA Desaturase-1 Protects Cells against Lipotoxicity-Mediated Apoptosis in Proximal Tubular Cells

    PubMed Central

    Iwai, Tamaki; Kume, Shinji; Chin-Kanasaki, Masami; Kuwagata, Shogo; Araki, Hisazumi; Takeda, Naoko; Sugaya, Takeshi; Uzu, Takashi; Maegawa, Hiroshi; Araki, Shin-ichi

    2016-01-01

    Saturated fatty acid (SFA)-related lipotoxicity is a pathogenesis of diabetes-related renal proximal tubular epithelial cell (PTEC) damage, closely associated with a progressive decline in renal function. This study was designed to identify a free fatty acid (FFA) metabolism-related enzyme that can protect PTECs from SFA-related lipotoxicity. Among several enzymes involved in FFA metabolism, we identified stearoyl-CoA desaturase-1 (SCD1), whose expression level significantly decreased in the kidneys of high-fat diet (HFD)-induced diabetic mice, compared with non-diabetic mice. SCD1 is an enzyme that desaturates SFAs, converting them to monounsaturated fatty acids (MUFAs), leading to the formation of neutral lipid droplets. In culture, retrovirus-mediated overexpression of SCD1 or MUFA treatment significantly ameliorated SFA-induced apoptosis in PTECs by enhancing intracellular lipid droplet formation. In contrast, siRNA against SCD1 exacerbated the apoptosis. Both overexpression of SCD1 and MUFA treatment reduced SFA-induced apoptosis via reducing endoplasmic reticulum stress in cultured PTECs. Thus, HFD-induced decrease in renal SCD1 expression may play a pathogenic role in lipotoxicity-induced renal injury, and enhancing SCD1-mediated desaturation of SFA and subsequent formation of neutral lipid droplets may become a promising therapeutic target to reduce SFA-induced lipotoxicity. The present study provides a novel insight into lipotoxicity in the pathogenesis of diabetic nephropathy. PMID:27834856

  2. Deficiency of stearoyl-CoA desaturase-1 aggravates colitogenic potential of adoptively transferred effector T cells.

    PubMed

    Yeoh, Beng San; Saha, Piu; Singh, Vishal; Xiao, Xia; Ying, Yun; Vanamala, Jairam K; Kennett, Mary J; Harvatine, Kevin J; Joe, Bina; Vijay-Kumar, Matam

    2016-10-01

    Stearoyl-CoA desaturase-1 (SCD1) is a lipogenic enzyme involved in the de novo biosynthesis of oleate (C18:1, n9), a major fatty acid in the phospholipids of lipid bilayers of cell membranes. Accordingly, Scd1KO mice display substantially reduced oleate in cell membranes. An altered SCD1 level was observed during intestinal inflammation; however, its role in modulating inflammatory bowel disease remains elusive. Herein, we investigated the colitogenic capacity of Scd1KO effector T cells by employing the adoptive T-cell transfer colitis model. Splenic effector T cells (CD4(+)CD25(-)) from age- and sex-matched wild-type (WT) and Scd1KO mice were isolated by FACS and intraperitoneally administered to Rag1KO mice, which were monitored for the development of colitis. At day 60 postcell transfer, Rag1KO mice that received Scd1KO CD4(+)CD25(-) T cells displayed accelerated and exacerbated colitis than mice receiving WT CD4(+)CD25(-) T cells. Intriguingly, Scd1KO CD4(+)CD25(-) T cells display augmented inflammatory cytokine profile and cellular membrane fluidity with a concomitant increase in proinflammatory saturated fatty acids, which we postulate to potentially underlie their augmented colitogenic potential.

  3. The anticancer gene ORCTL3 targets stearoyl-CoA desaturase-1 for tumour-specific apoptosis

    PubMed Central

    AbuAli, G; Chaisaklert, W; Stelloo, E; Pazarentzos, E; Hwang, M-S; Qize, D; Harding, SV; Al-Rubaish, A; Alzahrani, A-H; Al-Ali, A; Sanders, TAB; Aboagye, E O; Grimm, S

    2014-01-01

    ORCTL3 is a member of a group of genes, the so-called anticancer genes, that cause tumour-specific cell death. We show that this activity is triggered in isogenic renal cells upon their transformation independently of the cells’ proliferation status. For its cell death effect ORCTL3 targets the enzyme stearoyl-CoA desaturase-1 (SCD1) in fatty acid metabolism. This is caused by transmembrane domains 3 and 4, which are more efficacious in vitro than a low molecular weight drug against SCD1, and critically depend on their expression level. SCD1 is found upregulated upon renal cell transformation indicating that its activity, while not impacting proliferation, represents a critical bottleneck for tumourigenesis. An adenovirus expressing ORCTL3 leads to growth inhibition of renal tumours in vivo and to substantial destruction of patients’ kidney tumour cells ex vivo. Our results indicate fatty acid metabolism as a target for tumour-specific apoptosis in renal tumours and suggest ORCTL3 as a means to accomplish this. PMID:24769897

  4. Characterization of a stearoyl-acyl carrier protein desaturase gene family from chocolate tree, Theobroma cacao L.

    PubMed

    Zhang, Yufan; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    In plants, the conversion of stearoyl-ACP to oleoyol-ACP is catalyzed by a plastid-localized soluble stearoyl-acyl carrier protein (ACP) desaturase (SAD). The activity of SAD significantly impacts the ratio of saturated and unsaturated fatty acids, and is thus a major determinant of fatty acid composition. The cacao genome contains eight putative SAD isoforms with high amino acid sequence similarities and functional domain conservation with SAD genes from other species. Sequence variation in known functional domains between different SAD family members suggested that these eight SAD isoforms might have distinct functions in plant development, a hypothesis supported by their diverse expression patterns in various cacao tissues. Notably, TcSAD1 is universally expressed across all the tissues, and its expression pattern in seeds is highly correlated with the dramatic change in fatty acid composition during seed maturation. Interestingly, TcSAD3 and TcSAD4 appear to be exclusively and highly expressed in flowers, functions of which remain unknown. To test the function of TcSAD1 in vivo, transgenic complementation of the Arabidopsis ssi2 mutant was performed, demonstrating that TcSAD1 successfully rescued all AtSSI2 related phenotypes further supporting the functional orthology between these two genes. The identification of the major SAD gene responsible for cocoa butter biosynthesis provides new strategies for screening for novel genotypes with desirable fatty acid compositions, and for use in breeding programs to help pyramid genes for quality and other traits such as disease resistance.

  5. Characterization of a stearoyl-acyl carrier protein desaturase gene family from chocolate tree, Theobroma cacao L

    PubMed Central

    Zhang, Yufan; Maximova, Siela N.; Guiltinan, Mark J.

    2015-01-01

    In plants, the conversion of stearoyl-ACP to oleoyol-ACP is catalyzed by a plastid-localized soluble stearoyl-acyl carrier protein (ACP) desaturase (SAD). The activity of SAD significantly impacts the ratio of saturated and unsaturated fatty acids, and is thus a major determinant of fatty acid composition. The cacao genome contains eight putative SAD isoforms with high amino acid sequence similarities and functional domain conservation with SAD genes from other species. Sequence variation in known functional domains between different SAD family members suggested that these eight SAD isoforms might have distinct functions in plant development, a hypothesis supported by their diverse expression patterns in various cacao tissues. Notably, TcSAD1 is universally expressed across all the tissues, and its expression pattern in seeds is highly correlated with the dramatic change in fatty acid composition during seed maturation. Interestingly, TcSAD3 and TcSAD4 appear to be exclusively and highly expressed in flowers, functions of which remain unknown. To test the function of TcSAD1 in vivo, transgenic complementation of the Arabidopsis ssi2 mutant was performed, demonstrating that TcSAD1 successfully rescued all AtSSI2 related phenotypes further supporting the functional orthology between these two genes. The identification of the major SAD gene responsible for cocoa butter biosynthesis provides new strategies for screening for novel genotypes with desirable fatty acid compositions, and for use in breeding programs to help pyramid genes for quality and other traits such as disease resistance. PMID:25926841

  6. The evolutionary history of the stearoyl-CoA desaturase gene family in vertebrates

    PubMed Central

    2011-01-01

    Background Stearoyl-CoA desaturases (SCDs) are key enzymes involved in de novo monounsaturated fatty acid synthesis. They catalyze the desaturation of saturated fatty acyl-CoA substrates at the delta-9 position, generating essential components of phospholipids, triglycerides, cholesterol esters and wax esters. Despite being crucial for interpreting SCDs roles across species, the evolutionary history of the SCD gene family in vertebrates has yet to be elucidated, in particular their isoform diversity, origin and function. This work aims to contribute to this fundamental effort. Results We show here, through comparative genomics and phylogenetics that the SCD gene family underwent an unexpectedly complex history of duplication and loss events. Paralogy analysis hints that SCD1 and SCD5 genes emerged as part of the whole genome duplications (2R) that occurred at the stem of the vertebrate lineage. The SCD1 gene family expanded in rodents with the parallel loss of SCD5 in the Muridae family. The SCD1 gene expansion is also observed in the Lagomorpha although without the SCD5 loss. In the amphibian Xenopus tropicalis we find a single SCD1 gene but not SCD5, though this could be due to genome incompleteness. In the analysed teleost species no SCD5 is found, while the surrounding SCD5-less locus is conserved in comparison to tetrapods. In addition, the teleost SCD1 gene repertoire expanded to two copies as a result of the teleost specific genome duplication (3R). Finally, we describe clear orthologues of SCD1 and SCD5 in the chondrichthian, Scyliorhinus canicula, a representative of the oldest extant jawed vertebrate clade. Expression analysis in S. canicula shows that whilst SCD1 is ubiquitous, SCD5 is mainly expressed in the brain, a pattern which might indicate an evolutionary conserved function. Conclusion We conclude that the SCD1 and SCD5 genes emerged as part of the 2R genome duplications. We propose that the evolutionary conserved gene expression between distinct

  7. Cloning and characterization of the phytoene desaturase ( pds) gene — a key enzyme for carotenoids synthesis in Dunaliella (Chlorophyta)

    NASA Astrophysics Data System (ADS)

    Sun, Guohua; Sui, Zhenghong; Zhang, Xuecheng

    2008-08-01

    The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga, phytoene desaturase ( pds) gene cDNA together with its DNA sequences were isolated and their structures and functions analyzed. The full-length pds cDNA of 2290 bp (GenBank Accession No. DQ243892) was deduced from RACE results, including untranslated 21 bp 5'-and 520 bp 3'-flanking regions and an open reading frame of 582 amino acids, coding a protein of 64.196 kDa. The DNA sequence of 2908 bp (GenBank Accession No. DQ845248) including five introns was obtained. The fifth intron was uncompleted and complex, including two bases’ perfect repeats (GT)10 and large different-sized repeats within the last 400 bp. The Southern blot hybridization result demonstrated that this gene occurred as a single copy in this species, and the quantitative RT-PCR result showed that the transcription of this gene was constitutive. The evolutional significance of pds was discussed.

  8. Expression of C-5 sterol desaturase from an edible mushroom in fisson yeast enhances its ethanol and thermotolerance.

    PubMed

    Kamthan, Ayushi; Kamthan, Mohan; Datta, Asis

    2017-01-01

    Bioethanol is an environment friendly and renewable source of energy produced by the fermentation of agricultural raw material by a variety of microorganisms including yeast. Obtaining yeast strains that are tolerant to stresses like high levels of ethanol and high temperature is highly desirable as it reduces cost and increases yield during bioethanol production. Here, we report that heterologous expression of C-5 Sterol desaturase (FvC5SD)-an ergosterol biosynthesis enzyme from an edible mushroom Flammulina velutipes in fission yeast, not only imparts increased thermotolerance but also tolerance towards high ethanol concentration and low pH. This tolerance could be attributed to an increase of ≈1.5 fold in the level of ergosterol and oleic acid (C-18 unsaturated fatty acid) as analysed by gas chromatography- mass spectrometry. FvC5SD is a membrane localized iron binding enzyme that introduces double bond at C-5 position into the Δ7-sterol substrates to yield Δ5, 7- sterols as products. In F. velutipes, FvC5SD transcript was observed to be upregulated by ≈5 fold under low pH condition and by ≈ 9 folds and ≈5 fold at 40°C and 4°C respectively when compared to normal growth temperature of 23°C. Besides, susceptibility to cell wall inhibiting drugs like Congo red and Calcoflour white was also found to increase in FvC5SD expressing S. pombe strain. Alteration in membrane sterol and fatty acid composition could also lead to increase in susceptibility to cell wall inhibiting drugs. Thus, this study has immense industrial application and can be employed to ensure competitiveness of fermentation process.

  9. Expression of C-5 sterol desaturase from an edible mushroom in fisson yeast enhances its ethanol and thermotolerance

    PubMed Central

    Kamthan, Ayushi; Kamthan, Mohan; Datta, Asis

    2017-01-01

    Bioethanol is an environment friendly and renewable source of energy produced by the fermentation of agricultural raw material by a variety of microorganisms including yeast. Obtaining yeast strains that are tolerant to stresses like high levels of ethanol and high temperature is highly desirable as it reduces cost and increases yield during bioethanol production. Here, we report that heterologous expression of C-5 Sterol desaturase (FvC5SD)—an ergosterol biosynthesis enzyme from an edible mushroom Flammulina velutipes in fission yeast, not only imparts increased thermotolerance but also tolerance towards high ethanol concentration and low pH. This tolerance could be attributed to an increase of ≈1.5 fold in the level of ergosterol and oleic acid (C-18 unsaturated fatty acid) as analysed by gas chromatography- mass spectrometry. FvC5SD is a membrane localized iron binding enzyme that introduces double bond at C-5 position into the Δ7-sterol substrates to yield Δ5, 7- sterols as products. In F. velutipes, FvC5SD transcript was observed to be upregulated by ≈5 fold under low pH condition and by ≈ 9 folds and ≈5 fold at 40°C and 4°C respectively when compared to normal growth temperature of 23°C. Besides, susceptibility to cell wall inhibiting drugs like Congo red and Calcoflour white was also found to increase in FvC5SD expressing S. pombe strain. Alteration in membrane sterol and fatty acid composition could also lead to increase in susceptibility to cell wall inhibiting drugs. Thus, this study has immense industrial application and can be employed to ensure competitiveness of fermentation process. PMID:28278249

  10. Down-regulation of hepatic stearoyl-CoA desaturase-1 expression by fucoxanthin via leptin signaling in diabetic/obese KK-A(y) mice.

    PubMed

    Beppu, Fumiaki; Hosokawa, Masashi; Yim, Mi-Jin; Shinoda, Taro; Miyashita, Kazuo

    2013-05-01

    Stearoyl-coenzyme A desaturase-1 (SCD1) is a rate-limiting enzyme that catalyzes the biosynthesis of monounsaturated fatty acids from saturated fatty acids. Recently, SCD1 down-regulation has been implicated in the prevention of obesity, and the improvement of insulin and leptin sensitivity. In this study, we examined the effect of fucoxanthin, a marine carotenoid, on hepatic SCD1 in obese mouse models of hyperleptinemia KK-A(y) and leptin-deficiency ob/ob. In KK-A(y) mice, providing a diet containing 0.2 % fucoxanthin for 2 weeks markedly suppressed SCD1 mRNA and protein expressions in the liver. The fatty acid composition of liver lipids was also affected by an observed decrease in the ratio of oleic acid to stearic acid. Furthermore, serum leptin levels were significantly decreased in hyperleptinemia KK-A(y) mice after 2 weeks of fucoxanthin feeding. However, the suppressive effects of fucoxanthin on hepatic SCD1 and body weight gain were not observed in ob/ob mice. These results show that fucoxanthin down-regulates SCD1 expression and alters fatty acid composition of the liver via regulation of leptin signaling in hyperleptinemia KK-A(y) mice but not in leptin-deficient ob/ob mice.

  11. Characterization of the fungal gibberellin desaturase as a 2-oxoglutarate-dependent dioxygenase and its utilization for enhancing plant growth.

    PubMed

    Bhattacharya, Anjanabha; Kourmpetli, Sofia; Ward, Dennis A; Thomas, Stephen G; Gong, Fan; Powers, Stephen J; Carrera, Esther; Taylor, Benjamin; de Caceres Gonzalez, Francisco Nuñez; Tudzynski, Bettina; Phillips, Andrew L; Davey, Michael R; Hedden, Peter

    2012-10-01

    The biosynthesis of gibberellic acid (GA(3)) by the fungus Fusarium fujikuroi is catalyzed by seven enzymes encoded in a gene cluster. While four of these enzymes are characterized as cytochrome P450 monooxygenases, the nature of a fifth oxidase, GA(4) desaturase (DES), is unknown. DES converts GA(4) to GA(7) by the formation of a carbon-1,2 double bond in the penultimate step of the pathway. Here, we show by expression of the des complementary DNA in Escherichia coli that DES has the characteristics of a 2-oxoglutarate-dependent dioxygenase. Although it has low amino acid sequence homology with known 2-oxoglutarate-dependent dioxygenases, putative iron- and 2-oxoglutarate-binding residues, typical of such enzymes, are apparent in its primary sequence. A survey of sequence databases revealed that homologs of DES are widespread in the ascomycetes, although in most cases the homologs must participate in non-gibberellin (GA) pathways. Expression of des from the cauliflower mosaic virus 35S promoter in the plant species Solanum nigrum, Solanum dulcamara, and Nicotiana sylvestris resulted in substantial growth stimulation, with a 3-fold increase in height in S. dulcamara compared with controls. In S. nigrum, the height increase was accompanied by a 20-fold higher concentration of GA(3) in the growing shoots than in controls, although GA(1) content was reduced. Expression of des was also shown to partially restore growth in plants dwarfed by ectopic expression of a GA 2-oxidase (GA-deactivating) gene, consistent with GA(3) being protected from 2-oxidation. Thus, des has the potential to enable substantial growth increases, with practical implications, for example, in biomass production.

  12. [Substrate specificity of carotenoid 3',4'-desaturase from Deinococcus radiodurans].

    PubMed

    Sun, Zongtao; Tian, Bing; Shen, Shaochuan; Hu, Yuejin

    2010-10-01

    To examine the substrate specificity of carotenoid 3',4'-desaturase (DR2250) from Deinococcus radiodurans, we amplified the dr2250 gene by using PCR methods. The PCR products were digested by Hind III-BamH I and ligated into the vector pUC19, yielding recombinant vector pUC-CRTD. We analyzed the carotenoids of E. coli transformants containing pACCRT-EBI(Eu) and (or) pRK-CRTC and (or) pUC-CRTD. Our results demonstrated that DR2250 had substrate specificity on the carotenoids with hydroxyl group at C1 (1').

  13. Heating of vegetable oils influences the activity of enzymes participating in arachidonic acid formation in Wistar rats.

    PubMed

    Stawarska, Agnieszka; Białek, Agnieszka; Tokarz, Andrzej

    2015-10-01

    Dietary intake of lipids and their fatty acids profile influence many aspects of health. Thermal processing changes the properties of edible oils and can also modify their metabolism, for example, eicosanoids formation. The aim of our study was to verify whether the activity of desaturases can be modified by lipids intake, especially by the fatty acids content. The experimental diets contained rapeseed oil, sunflower oil, and olive oil, both unheated and heated (for 10 minutes at 200 °C each time before administration), and influenced the fatty acids composition in serum and the activity of enzymes participating in arachidonic acid (AA) formation. The activity of desaturases was determined by measuring the amounts of AA formed in vitro derived from linoleic acid as determined in liver microsomes of Wistar rats. In addition, the indices of ∆(6)-desaturase (D6D) and ∆(5)-desaturase (D5D) have been determined. To realize this aim, the method of high-performance liquid chromatography has been used with ultraviolet-visible spectrophotometry detection. Diet supplementation with the oils rich in polyunsaturated fatty acids affects the fatty acids profile in blood serum and the activity of D6D and ∆(5)-desaturase in rat liver microsomes, the above activities being dependent on the kind of oil applied. Diet supplementation with heated oils has been found to increase the amount of AA produced in hepatic microsomes; and in the case of rapeseed oil and sunflower oil, it has also increased D6D activity.

  14. Identification of Stearoyl-CoA Desaturase (SCD) Gene Interactions in Korean Native Cattle Based on the Multifactor-dimensionality Reduction Method.

    PubMed

    Oh, Dong-Yep; Jin, Me-Hyun; Lee, Yoon-Seok; Ha, Jae-Jung; Kim, Byung-Ki; Yeo, Jung-Sou; Lee, Jea-Young

    2013-09-01

    Fat quality is determined by the composition of fatty acids. Genetic relationships between this composition and single nucleotide polymorphisms (SNPs) in the stearoyl-CoA desaturase1 (SCD1) gene were examined using 513 Korean native cattle. Single and epistatic effects of 7 SNP genetic variations were investigated, and the multifactor dimensionality reduction (MDR) method was used to investigate gene interactions in terms of oleic acid (C18:1), mono-unsaturated fatty acids (MUFAs) and marbling score (MS). The g.6850+77 A>G and g.14047 C>T SNP interactions were identified as the statistically optimal combination (C18:1, MUFAs and MS permutation p-values were 0.000, 0.000 and 0.001 respectively) of two-way gene interactions. The interaction effects of g.6850+77 A>G, g.10213 T>C and g.14047 C>T reflected the highest training-balanced accuracy (63.76%, 64.70% and 61.85% respectively) and was better than the individual effects for C18:1, MUFAs and MS. In addition, the superior genotype groups were AATTCC, AGTTCC, GGTCCC, AGTCCT, GGCCCT and AGCCTT. These results suggest that the selected SNP combination of the SCD1 gene and superior genotype groups can provide useful inferences for the improvement of the fatty acid composition in Korean native cattle.

  15. Identification of Stearoyl-CoA Desaturase (SCD) Gene Interactions in Korean Native Cattle Based on the Multifactor-dimensionality Reduction Method

    PubMed Central

    Oh, Dong-yep; Jin, Me-hyun; Lee, Yoon-seok; Ha, Jae-jung; Kim, Byung-ki; Yeo, Jung-sou; Lee, Jea-young

    2013-01-01

    Fat quality is determined by the composition of fatty acids. Genetic relationships between this composition and single nucleotide polymorphisms (SNPs) in the stearoyl-CoA desaturase1 (SCD1) gene were examined using 513 Korean native cattle. Single and epistatic effects of 7 SNP genetic variations were investigated, and the multifactor dimensionality reduction (MDR) method was used to investigate gene interactions in terms of oleic acid (C18:1), mono-unsaturated fatty acids (MUFAs) and marbling score (MS). The g.6850+77 A>G and g.14047 C>T SNP interactions were identified as the statistically optimal combination (C18:1, MUFAs and MS permutation p-values were 0.000, 0.000 and 0.001 respectively) of two-way gene interactions. The interaction effects of g.6850+77 A>G, g.10213 T>C and g.14047 C>T reflected the highest training-balanced accuracy (63.76%, 64.70% and 61.85% respectively) and was better than the individual effects for C18:1, MUFAs and MS. In addition, the superior genotype groups were AATTCC, AGTTCC, GGTCCC, AGTCCT, GGCCCT and AGCCTT. These results suggest that the selected SNP combination of the SCD1 gene and superior genotype groups can provide useful inferences for the improvement of the fatty acid composition in Korean native cattle. PMID:25049903

  16. Enhancement of carotenoid production by disrupting the C22-sterol desaturase gene (CYP61) in Xanthophyllomyces dendrorhous

    PubMed Central

    2012-01-01

    Background Xanthophyllomyces dendrorhous is a basidiomycetous yeast that synthesizes astaxanthin, which is a carotenoid with a great biotechnological impact. The ergosterol and carotenoid synthesis pathways are derived from the mevalonate pathway, and in both pathways, cytochrome P450 enzymes are involved. Results In this study, we isolated and described the X. dendrorhous CYP61 gene, which encodes a cytochrome P450 involved in ergosterol biosynthesis. This gene is composed of nine exons and encodes a 526 amino acid polypeptide that shares significant percentages of identity and similitude with the C22-sterol desaturase, CYP61, from other fungi. Mutants derived from different parental strains were obtained by disrupting the CYP61 gene with an antibiotic selection marker. These mutants were not able to produce ergosterol and accumulated ergosta-5,8,22-trien-3-ol and ergosta-5,8-dien-3-ol. Interestingly, all of the mutants had a more intense red color phenotype than their respective parental strains. The carotenoid composition was qualitatively and quantitatively analyzed by RP-HPLC, revealing that the carotenoid content was higher in the mutant strains without major changes in their composition. The expression of the HMGR gene, which encodes an enzyme involved in the mevalonate pathway (3-hydroxy-3-methylglutaryl-CoA reductase), was analyzed by RT-qPCR showing that its transcript levels are higher in the CYP61 mutants. Conclusions These results suggest that in X. dendrorhous, ergosterol regulates HMGR gene expression by a negative feedback mechanism and in this way; it contributes in the regulation of the carotenoid biosynthesis. PMID:23075035

  17. Stearoyl-acyl carrier protein desaturases are associated with floral isolation in sexually deceptive orchids

    PubMed Central

    Schlüter, Philipp M.; Xu, Shuqing; Gagliardini, Valeria; Whittle, Edward; Shanklin, John; Grossniklaus, Ueli; Schiestl, Florian P.

    2011-01-01

    The orchids Ophrys sphegodes and O. exaltata are reproductively isolated from each other by the attraction of two different, highly specific pollinator species. For pollinator attraction, flowers chemically mimic the pollinators’ sex pheromones, the key components of which are alkenes with different double-bond positions. This study identifies genes likely involved in alkene biosynthesis, encoding stearoyl-acyl carrier protein (ACP) desaturase (SAD) homologs. The expression of two isoforms, SAD1 and SAD2, is flower-specific and broadly parallels alkene production during flower development. SAD2 shows a significant association with alkene production, and in vitro assays show that O. sphegodes SAD2 has activity both as an 18:0-ACP Δ9 and a 16:0-ACP Δ4 desaturase. Downstream metabolism of the SAD2 reaction products would give rise to alkenes with double-bonds at position 9 or position 12, matching double-bond positions observed in alkenes in the odor bouquet of O. sphegodes. SAD1 and SAD2 show evidence of purifying selection before, and positive or relaxed purifying selection after gene duplication. By contributing to the production of species-specific alkene bouquets, SAD2 is suggested to contribute to differential pollinator attraction and reproductive isolation among these species. Taken together, these data are consistent with the hypothesis that SAD2 is a florally expressed barrier gene of large phenotypic effect and, possibly, a genic target of pollinator-mediated selection. PMID:21436056

  18. Carotenoid 3',4'-desaturase is involved in carotenoid biosynthesis in the radioresistant bacterium Deinococcus radiodurans.

    PubMed

    Tian, Bing; Sun, Zongtao; Xu, Zhenjian; Shen, Shaochuan; Wang, Hu; Hua, Yuejin

    2008-12-01

    Deinococcus radiodurans strain R1 synthesizes deinoxanthin, a unique carotenoid product, which contributes to cell resistance following various stresses. The biosynthetic pathway of deinoxanthin is unclear, although several enzymes are presumed to be involved. The gene (dr2250) predicted by gene homologue analysis to encode carotenoid 3',4'-desaturase (CrtD) was deleted to investigate its function. A mutant deficient in the gene homologue of crtLm (dr0801) was also constructed to verify the catalytic function of the gene product in the native host. Carotenoid analysis of the resultant mutants verified that DR2250 encodes carotenoid 3',4'-desaturase, which catalyses the C-3',4'-desaturation of the monocyclic precursor of deinoxanthin but not acyclic carotenoids. Mutation of the gene homologue of crtLm (dr0801) resulted in accumulation of lycopene, confirming that it encodes the lycopene cyclase in the native host. The lack of CrtD decreased the antioxidant capacity of the mutant deficient in dr2250 compared with the wild-type, indicating that the C-3',4'-desaturation step contributes to the antioxidant capacity of deinoxanthin in D. radiodurans.

  19. Stearoyl-acyl carrier protein desaturases are associated with floral isolation in sexually deceptive orchids.

    PubMed

    Schlüter, Philipp M; Xu, Shuqing; Gagliardini, Valeria; Whittle, Edward; Shanklin, John; Grossniklaus, Ueli; Schiestl, Florian P

    2011-04-05

    The orchids Ophrys sphegodes and O. exaltata are reproductively isolated from each other by the attraction of two different, highly specific pollinator species. For pollinator attraction, flowers chemically mimic the pollinators' sex pheromones, the key components of which are alkenes with different double-bond positions. This study identifies genes likely involved in alkene biosynthesis, encoding stearoyl-acyl carrier protein (ACP) desaturase (SAD) homologs. The expression of two isoforms, SAD1 and SAD2, is flower-specific and broadly parallels alkene production during flower development. SAD2 shows a significant association with alkene production, and in vitro assays show that O. sphegodes SAD2 has activity both as an 18:0-ACP Δ(9) and a 16:0-ACP Δ(4) desaturase. Downstream metabolism of the SAD2 reaction products would give rise to alkenes with double-bonds at position 9 or position 12, matching double-bond positions observed in alkenes in the odor bouquet of O. sphegodes. SAD1 and SAD2 show evidence of purifying selection before, and positive or relaxed purifying selection after gene duplication. By contributing to the production of species-specific alkene bouquets, SAD2 is suggested to contribute to differential pollinator attraction and reproductive isolation among these species. Taken together, these data are consistent with the hypothesis that SAD2 is a florally expressed barrier gene of large phenotypic effect and, possibly, a genic target of pollinator-mediated selection.

  20. Stearoyl-acyl carrier protein desaturases are associated with floral isolation in sexually deceptive orchids

    SciTech Connect

    Schluter, P.M.; Shanklin, J.; Xu, S.; Gagliardini, V.; Whittle, E.; Grossniklaus, U.; Schiestl, F. P.

    2011-04-05

    The orchids Ophrys sphegodes and O. exaltata are reproductively isolated from each other by the attraction of two different, highly specific pollinator species. For pollinator attraction, flowers chemically mimic the pollinators sex pheromones, the key components of which are alkenes with different double-bond positions. This study identifies genes likely involved in alkene biosynthesis, encoding stearoyl-acyl carrier protein (ACP) desaturase (SAD) homologs. The expression of two isoforms, SAD1 and SAD2, is flower-specific and broadly parallels alkene production during flower development. SAD2 shows a significant association with alkene production, and in vitro assays show that O. sphegodes SAD2 has activity both as an 18:0-ACP {Delta}{sup 9} and a 16:0-ACP {Delta}{sup 4} desaturase. Downstream metabolism of the SAD2 reaction products would give rise to alkenes with double-bonds at position 9 or position 12, matching double-bond positions observed in alkenes in the odor bouquet of O. sphegodes. SAD1 and SAD2 show evidence of purifying selection before, and positive or relaxed purifying selection after gene duplication. By contributing to the production of species-specific alkene bouquets, SAD2 is suggested to contribute to differential pollinator attraction and reproductive isolation among these species. Taken together, these data are consistent with the hypothesis that SAD2 is a florally expressed barrier gene of large phenotypic effect and, possibly, a genic target of pollinator-mediated selection.

  1. Phytoene Desaturase from Oryza sativa: Oligomeric Assembly, Membrane Association and Preliminary 3D-Analysis

    PubMed Central

    Koschmieder, Julian; Brausemann, Anton; Drepper, Friedel; Rodriguez-Franco, Marta; Ghisla, Sandro; Warscheid, Bettina; Einsle, Oliver; Beyer, Peter

    2015-01-01

    Recombinant phytoene desaturase (PDS-His6) from rice was purified to near-homogeneity and shown to be enzymatically active in a biphasic, liposome-based assay system. The protein contains FAD as the sole protein-bound redox-cofactor. Benzoquinones, not replaceable by molecular oxygen, serve as a final electron acceptor defining PDS as a 15-cis-phytoene (donor):plastoquinone oxidoreductase. The herbicidal PDS-inhibitor norflurazon is capable of arresting the reaction by stabilizing the intermediary FADred, while an excess of the quinone acceptor relieves this blockage, indicating competition. The enzyme requires its homo-oligomeric association for activity. The sum of data collected through gel permeation chromatography, non-denaturing polyacrylamide electrophoresis, chemical cross-linking, mass spectrometry and electron microscopy techniques indicate that the high-order oligomers formed in solution are the basis for an active preparation. Of these, a tetramer consisting of dimers represents the active unit. This is corroborated by our preliminary X-ray structural analysis that also revealed similarities of the protein fold with the sequence-inhomologous bacterial phytoene desaturase CRTI and other oxidoreductases of the GR2-family of flavoproteins. This points to an evolutionary relatedness of CRTI and PDS yielding different carotene desaturation sequences based on homologous protein folds. PMID:26147209

  2. Erythrocyte and plasma fatty acid patterns in dogs with atopic dermatitis and healthy dogs in the same household

    PubMed Central

    Zimmermann, Annett; Gück, Thomas; Oechtering, Gerhard

    2006-01-01

    Abstract Recent studies have indicated that dogs with canine atopic dermatitis (CAD) may have a disorder of fatty acid metabolism: possibly low or absent activity of Δ6-desaturase or Δ5-desaturase, or both. To clarify this possibility, we examined the erythrocyte and plasma fatty acid patterns of 8 dogs with CAD and their 8 healthy housemates. Atopic dermatitis was diagnosed according to the criteria proposed by Willemse; other causes of dermatitis were excluded clinically and by appropriate tests. Erythrocyte ghosts were prepared from blood samples. Membrane lipids were extracted and separated by thin-layer chromatography. From plasma and lipid fractions, fatty acid content was determined by gas chromatography. In erythrocytes, but not in plasma, we observed significant differences in the fatty acid pattern that suggested a reduction in the n6 fatty acid products of the Δ6- and Δ5-desaturases in dogs with atopic dermatitis when compared with healthy housemates. PMID:16850941

  3. The role of cytochrome b5 in delta 12 desaturation of oleic acid by microsomes of safflower (Carthamus tinctorius L.).

    PubMed

    Kearns, E V; Hugly, S; Somerville, C R

    1991-02-01

    The electron donors for the membrane-bound fatty acid desaturases of higher plants have not previously been identified. In order to assess the participation of cytochrome b5 in microsomal fatty acid desaturation, the cytoplasmic domain of microsomal cytochrome b5 was purified from Brassica oleracea, and murine polyclonal antibodies were prepared. The IgG fraction from ascites fluid inhibited 62% of NADH-dependent cytochrome c reduction in safflower (Carthamus tinctorius L.) microsomes. These antibodies also blocked desaturation of oleic acid to linoleic acid in lipids of C. tinctorius microsomes by 93%, suggesting that cytochrome b5 is the electron donor for the delta 12 desaturase.

  4. Genome-wide analysis of the omega-3 fatty acid desaturase gene family in Gossypium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid ...

  5. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank; Boddupalli, Sekhar S.

    2011-08-23

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  6. Production of hydroxylated fatty acids in genetically modified plants

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank; Boddupalli, Sekhar S.

    2005-08-30

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  7. Non-destructive determination of high oleic acid content in single soybean seeds by near infrared reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean with increased oleic acid is desirable to improve oxidative stability and functionality of soybean seed oil. Recently, soybean genotypes with high oleic acid (= 70%) were developed by conventional breeding and molecular genetic selection of mutant fatty acid desaturase alleles. Determination...

  8. Discovery of Tumor-Specific Irreversible Inhibitors of Stearoyl CoA Desaturase

    PubMed Central

    Theodoropoulos, Panayotis C.; Gonzales, Stephen S.; Winterton, Sarah E.; Rodriguez-Navas, Carlos; McKnight, John S.; Morlock, Lorraine K.; Hanson, Jordan M.; Cross, Bethany; Owen, Amy E.; Duan, Yingli; Moreno, Jose R.; Lemoff, Andrew; Mirzaei, Hamid; Posner, Bruce A.; Williams, Noelle S.

    2016-01-01

    A hallmark of targeted cancer therapies is selective toxicity among cancer cell lines. We evaluated results from a viability screen of over 200,000 small molecules to identify two chemical series, oxalamides and benzothiazoles, that were selectively toxic to the same four of 12 human lung cancer cell lines at low nanomolar concentrations. Sensitive cell lines expressed cytochrome P450 (CYP) 4F11, which metabolized the compounds into irreversible stearoyl CoA desaturase (SCD) inhibitors. SCD is recognized as a promising biological target in cancer and metabolic disease. However, SCD is essential to sebocytes, and accordingly SCD inhibitors cause skin toxicity. Mouse sebocytes were unable to activate the benzothiazoles or oxalamides into SCD inhibitors, providing a therapeutic window for inhibiting SCD in vivo. We thus offer a strategy to target SCD in cancer by taking advantage of high CYP expression in a subset of tumors. PMID:26829472

  9. A Novel Selective Inhibitor of Delta-5 Desaturase Lowers Insulin Resistance and Reduces Body Weight in Diet-Induced Obese C57BL/6J Mice

    PubMed Central

    Yashiro, Hiroaki; Takagahara, Shuichi; Tamura, Yumiko Okano; Miyahisa, Ikuo; Matsui, Junji; Suzuki, Hideo; Ikeda, Shota; Watanabe, Masanori

    2016-01-01

    Obesity is now recognized as a state of chronic low-grade inflammation and is called as metabolic inflammation. Delta-5 desaturase (D5D) is an enzyme that metabolizes dihomo-γ-linolenic acid (DGLA) to arachidonic acid (AA). Thus, D5D inhibition increases DGLA (precursor to anti-inflammatory eicosanoids) while decreasing AA (precursor to pro-inflammatory eicosanoids), and could result in synergistic improvement in the low-grade inflammatory state. Here, we demonstrate reduced insulin resistance and the anti-obesity effect of a D5D selective inhibitor (compound-326), an orally active small-molecule, in a high-fat diet-induced obese (DIO) mouse model. In vivo D5D inhibition was confirmed by determining changes in blood AA/DGLA profiles. In DIO mice, chronic treatment with compound-326 lowered insulin resistance and caused body weight loss without significant impact on cumulative calorie intake. Decreased macrophage infiltration into adipose tissue was expected from mRNA analysis. Increased daily energy expenditure was also observed following administration of compound-326, in line with sustained body weight loss. These data indicate that the novel D5D selective inhibitor, compound-326, will be a new class of drug for the treatment of obese and diabetic patients. PMID:27832159

  10. A low fat diet enhances polyunsaturated fatty acid desaturation and elongation independent of n3 enrichment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low fat diets are associated with risk reduction for chronic metabolic diseases compared to high fat diets. To evaluate effects of varied fat and fatty acid intake on lipid metabolism, phospholipid fatty acids (PLFA) were measured and delta 5 and 6 desaturase activities (D5D, D6D) were calculated in...

  11. Bacterial Degradation of tert-Amyl Alcohol Proceeds via Hemiterpene 2-Methyl-3-Buten-2-ol by Employing the Tertiary Alcohol Desaturase Function of the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ

    PubMed Central

    Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H.

    2012-01-01

    Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed. PMID:22194447

  12. Increasing ω-3 Desaturase Expression in Tomato Results in Altered Aroma Profile and Enhanced Resistance to Cold Stress1[W][OA

    PubMed Central

    Domínguez, Teresa; Hernández, M. Luisa; Pennycooke, Joyce C.; Jiménez, Pedro; Martínez-Rivas, José Manuel; Sanz, Carlos; Stockinger, Eric J.; Sánchez-Serrano, José J.; Sanmartín, Maite

    2010-01-01

    One of the drawbacks in improving the aroma properties of tomato (Solanum lycopersicum) fruit is the complexity of this organoleptic trait, with a great variety of volatiles contributing to determine specific quality features. It is well established that the oxylipins hexanal and (Z)-hex-3-enal, synthesized through the lipoxygenase pathway, are among the most important aroma compounds and impart in a correct proportion some of the unique fresh notes in tomato. Here, we confirm that all enzymes responsible for the synthesis of these C6 compounds are present and active in tomato fruit. Moreover, due to the low odor threshold of (Z)-hex-3-enal, small changes in the concentration of this compound could modify the properties of the tomato fruit aroma. To address this possibility, we have overexpressed the ω-3 fatty acid desaturases FAD3 and FAD7 that catalyze the conversion of linoleic acid (18:2) to linolenic acid (18:3), the precursor of hexenals and its derived alcohols. Transgenic OE-FAD tomato plants exhibit altered fatty acid composition, with an increase in the 18:3/18:2 ratio in leaves and fruits. These changes provoke a clear variation in the C6 content that results in a significant alteration of the (Z)-hex-3-enal/hexanal ratio that is particularly important in ripe OE-FAD3FAD7 fruits. In addition to this effect on tomato volatile profile, OE-FAD tomato plants are more tolerant to chilling. However, the different behaviors of OE-FAD plants underscore the existence of separate fatty acid fluxes to ensure plant survival under adverse conditions. PMID:20382895

  13. Sphingolipid base modifying enzymes in sunflower (Helianthus annuus): cloning and characterization of a C4-hydroxylase gene and a new paralogous Δ8-desaturase gene.

    PubMed

    Moreno-Pérez, Antonio J; Martínez-Force, Enrique; Garcés, Rafael; Salas, Joaquín J

    2011-05-15

    Sphingolipids are components of plant cell membranes that participate in the regulation of important physiological processes. Unlike their animal counterparts, plant sphingolipids are characterized by high levels of base C4-hydroxylation. Moreover, desaturation at the Δ8 position predominates over the Δ4 desaturation typically found in animal sphingolipids. These modifications are due to the action of C4-hydroxylases and Δ8-long chain base desaturases, and they are important for complex sphingolipids finally becoming functional. The long chain bases of sunflower sphingolipids have high levels of hydroxylated and unsaturated moieties. Here, a C4-long chain base hydroxylase was functionally characterized in sunflower plant, an enzyme that could complement the sur2Δ mutation when heterologously expressed in this yeast mutant deficient in hydroxylation. This hydroxylase was ubiquitously expressed in sunflower, with the highest levels found in the developing cotyledons. In addition, we identified a new Δ8-long base chain desaturase gene that displays strong homology to a previously reported desaturase gene. This desaturase was also expressed in yeast and was able to change the long chain base composition of the transformed host. We studied the expression of this desaturase and compared it with that of the other isoform described in sunflower. The desaturase form studied in this paper displayed higher expression levels in developing seeds.

  14. Effects of cigarette smoke on cell viability, linoleic acid metabolism and cholesterol synthesis, in THP-1 cells.

    PubMed

    Ghezzi, Silvia; Risé, Patrizia; Ceruti, Stefania; Galli, Claudio

    2007-07-01

    Cigarette smoke (CS) contains thousands of substances, mainly free radicals that have as a target the polyunsaturated fatty acids (PUFA). Long chain PUFA are produced through elongation and desaturation reactions from their precursors; the desaturation reactions are catalyzed by different enzymes: the conversion of 18:2n-6 (linoleic acid, LA) to 18:3n-6 by Delta6 desaturase, while that of 20:3n-6 to 20:4n-6 by Delta5 desaturase. The aim of this work is to evaluate the effect of serum exposed to cigarette smoke (SE-FBS) on (1) cell viability and proliferation, (2) [1-(14)C] LA conversion and desaturase activities in THP-1 cells, a monocytic cell line. In THP-1, CS inhibits cell proliferation dose-dependently, by producing a modification in the cell cycle with a reduced number of cells in synthesis and mitosis phases at higher concentrations. CS also decreases [1-(14)C] LA conversion to its derivatives in a concentration-dependent manner, inhibiting the activities of Delta6 and mainly Delta5 desaturase. In addition, CS does not modify the incorporation of LA into various lipid classes but it reduces cholesterol synthesis from radiolabelled acetate, and increases free fatty acid, TG and CE levels. In conclusion, CS affects lipid metabolism, inhibiting LA conversion and desaturase activities. CS also shifts the "de novo" lipid synthesis from free cholesterol to TG and CE, where LA is preferentially esterified.

  15. A Desaturase Gene Involved in the Formation of 1,14-Nonadecadiene in Synechococcus sp. Strain PCC 7002

    PubMed Central

    Mendez-Perez, Daniel; Herman, Nicolaus A.

    2014-01-01

    The marine cyanobacterium Synechococcus sp. strain PCC 7002 synthesizes two alkenes, 1-nonadecene and 1,14-nonadecadiene. Whereas the genetic basis for the biosynthesis of the terminal double bond in both alkenes has been characterized, the origin of the internal double bond in 1,14-nonadecadiene has not. In this study, we demonstrate that a gene encoding an uncharacterized desaturase is involved in the formation of the internal double bond of 1,14-nonadecadiene. Further, at low temperatures, the desaturase gene is essential for growth, and in wild-type cells the levels of 1,14-nonadecadiene increase relative to that of cells grown at 38°C. These data suggest that 1,14-nonadecadiene plays a role in responding to cold stress. PMID:25063658

  16. Transcriptome Characterisation of the Ant Formica exsecta with New Insights into the Evolution of Desaturase Genes in Social Hymenoptera

    PubMed Central

    Badouin, Hélène; Belkhir, Khalid; Gregson, Emma; Galindo, Juan; Sundström, Liselotte; Martin, Stephen J.; Butlin, Roger K.; Smadja, Carole M.

    2013-01-01

    Background Despite the recent sequencing of seven ant genomes, no genomic data are available for the genus Formica, an important group for the study of eusocial traits. We sequenced the transcriptome of the ant Formica exsecta with the 454 FLX Titanium technology from a pooled sample of workers from 70 Finnish colonies. Results About 1,000,000 reads were obtained from a normalised cDNA library. We compared the assemblers MIRA3.0 and Newbler2.6 and showed that the latter performed better on this dataset due to a new option which is dedicated to improve contig formation in low depth portions of the assemblies. The 29,579 contigs represent 27 Mb. 50% showed similarity with known proteins and 25% could be assigned a category of gene ontology. We found more than 13,000 high-quality single nucleotide polymorphisms. The Δ9 desaturase gene family is an important multigene family involved in chemical communication in insects. We found six Δ9 desaturases in this Formica exsecta transcriptome dataset that were used to reconstruct a maximum-likelihood phylogeny of insect desaturases and to test for signatures of positive selection in this multigene family in ant lineages. We found differences with previous phylogenies of this gene family in ants, and found two clades potentially under positive selection. Conclusion This first transcriptome reference sequence of Formica exsecta provided sequence and polymorphism data that will allow researchers working on Formica ants to develop studies to tackle the genetic basis of eusocial phenotypes. In addition, this study provided some general guidelines for de novo transcriptome assembly that should be useful for future transcriptome sequencing projects. Finally, we found potential signatures of positive selection in some clades of the Δ9 desaturase gene family in ants, which suggest the potential role of sequence divergence and adaptive evolution in shaping the large diversity of chemical cues in social insects. PMID:23874539

  17. Wheat germ cell-free translation, purification, and assembly of a functional human stearoyl-CoA desaturase complex.

    PubMed

    Goren, Michael A; Fox, Brian G

    2008-12-01

    A wheat germ cell-free extract was used to perform in vitro translation of human stearoyl-CoA desaturase in the presence of unilamelar liposomes, and near complete transfer of the expressed integral membrane protein into the liposome was observed. Moreover, co-translation of the desaturase along with human cytochrome b(5) led to transfer of both membrane proteins into the liposomes. A simple, single step purification via centrifugation in a density gradient yielded proteoliposomes with the desaturase in high purity as judged by capillary electrophoresis. After in vitro reconstitution of the non-heme iron and heme active sites, the function of the reconstituted enzyme complex was demonstrated by conversion of stearoyl-CoA to oleoyl-CoA. This simple translation approach obviates the use of detergents or other lipids to stabilize and isolate a catalytically active integral membrane enzyme. The applicability of cell-free translation to the assembly and purification of other integral membrane protein complexes is discussed.

  18. Increased stearoyl-CoA desaturase index and triglyceride content in the liver of rats after a single bout of swimming exercise.

    PubMed

    Ochiai, Masaru; Matsuo, Tatsuhiro

    2012-01-01

    Up-regulation of stearoyl-CoA desaturase (SCD) is closely related to improved insulin resistance. We investigated whether the SCD indices in tissues were influenced by a single-endurance exercise and low content of dietary medium-chain fatty acid (FA). Wistar rats were fed a long-chain (S) or medium- and long-chain FA (M) diet for 2 weeks. At the end of the experiment, the rats were further assigned to two sub-groups (sedentary, Sed; exercise, Ex). These groups were defined as S-Sed, S-Ex, M-Sed, and M-Ex. The rats in the exercise groups were subjected to swimming exercise for 4 h, and tissue samples were obtained. The exercise significantly increased the triglyceride (TG) content and SCD index only in the liver. In contrast, no such changes were apparent by intake of the M diet. A single bout of endurance exercise increased the hepatic TG content and SCD index which might be effective in protecting against insulin resistance.

  19. Skin-specific deletion of stearoyl-CoA desaturase-1 alters skin lipid composition and protects mice from high fat diet-induced obesity.

    PubMed

    Sampath, Harini; Flowers, Matthew T; Liu, Xueqing; Paton, Chad M; Sullivan, Ruth; Chu, Kiki; Zhao, Minghui; Ntambi, James M

    2009-07-24

    Stearoyl-CoA desaturase-1 (SCD1) catalyzes the synthesis of monounsaturated fatty acids and is an important regulator of whole body energy homeostasis. Severe cutaneous changes in mice globally deficient in SCD1 also indicate a role for SCD1 in maintaining skin lipids. We have generated mice with a skin-specific deletion of SCD1 (SKO) and report here that SKO mice display marked sebaceous gland hypoplasia and depletion of sebaceous lipids. In addition, SKO mice have significantly increased energy expenditure and are protected from high fat diet-induced obesity, thereby recapitulating the hypermetabolic phenotype of global SCD1 deficiency. Genes of fat oxidation, lipolysis, and thermogenesis, including uncoupling proteins and peroxisome proliferator-activated receptor-gamma co-activator-1alpha, are up-regulated in peripheral tissues of SKO mice. However, unlike mice globally deficient in SCD1, SKO mice have an intact hepatic lipogenic response to acute high carbohydrate feeding. Despite increased basal thermogenesis, SKO mice display severe cold intolerance because of rapid depletion of fuel substrates, including hepatic glycogen, to maintain core body temperature. These data collectively indicate that SKO mice have increased cold perception because of loss of insulating factors in the skin. This results in up-regulation of thermogenic processes for temperature maintenance at the expense of fuel economy, illustrating cross-talk between the skin and peripheral tissues in maintaining energy homeostasis.

  20. Abrogation of de novo lipogenesis by stearoyl-CoA desaturase 1 inhibition interferes with oncogenic signaling and blocks prostate cancer progression in mice

    PubMed Central

    Fritz, Vanessa; Benfodda, Zohra; Rodier, Geneviève; Henriquet, Corinne; Iborra, François; Avancès, Christophe; Allory, Yves; De La Taille, Alexandre; Culine, Stéphane; Blancou, Hubert; Cristol, Jean Paul; Michel, Françoise; Sardet, Claude; Fajas, Lluis

    2010-01-01

    Increased de novo fatty acid (FA) synthesis is one hallmark of tumor cells, including prostate cancer (PC). We present here our most recent results showing that lipids composition in human prostate cancer (PC) is characterized by an increased ratio of monounsaturated FA (MUFA) to saturated FA (SFA), compared to normal prostate, and evidence the overexpression of the lipogenic enzyme stearoyl CoA desaturase 1 (SCD1) in human PC. As a new therapeutic strategy, we show that pharmacological inhibition of SCD1 activity impairs lipid synthesis and results in decreased proliferation of both androgen-sensitive and androgen-resistant PC cells, abrogates the growth of prostate tumor xenografts in nude mice, and confers therapeutic benefit on animal survival. We show that these changes in lipid synthesis are translated into the inhibition of the AKT pathway, and that the decrease in concentration of phosphatidyl inositol tri-phosphate (PI (3,4,5)P3) might at least partially mediates this effect. Inhibition of SCD1 also promotes the activation of AMP-activated kinase (AMPK) and GSK3α/β, the latter on being consistent with a decrease in β-catenin activity and mRNA levels of various β-catenin growth promoting trancriptional targets. Furthermore, we show that activity is required for cell transformation by Ras oncogene. Together, our data support for the first time the concept of targeting the lipogenic enzyme SCD1 as a new promising therapeutic approach to block oncogenesis and PC progression. PMID:20530718

  1. Stearoyl-CoA Desaturase 1 Is a Key Determinant of Membrane Lipid Composition in 3T3-L1 Adipocytes

    PubMed Central

    Hagen, Rachel; Vidal-Puig, Antonio

    2016-01-01

    Stearoyl-CoA desaturase 1 (SCD1) is a lipogenic enzyme important for the regulation of membrane lipid homeostasis; dysregulation likely contributes to obesity associated metabolic disturbances. SCD1 catalyses the Δ9 desaturation of 12-19 carbon saturated fatty acids to monounsaturated fatty acids. To understand its influence in cellular lipid composition we investigated the effect of genetic ablation of SCD1 in 3T3-L1 adipocytes on membrane microdomain lipid composition at the species-specific level. Using liquid chromatography/electrospray ionisation-tandem mass spectrometry, we quantified 70 species of ceramide, mono-, di- and trihexosylceramide, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, bis(monoacylglycero)phosphate, phosphatidylinositol and cholesterol in 3T3-L1 adipocytes in which a 90% reduction in scd1 mRNA expression was achieved with siRNA. Cholesterol content was unchanged although decreases in other lipids resulted in cholesterol accounting for a higher proportion of lipid in the membranes. This was associated with decreased membrane lateral diffusion. An increased ratio of 24:0 to 24:1 in ceramide, mono- and dihexosylceramide, and sphingomyelin likely also contributed to this decrease in lateral diffusion. Of particular interest, we observed a decrease in phospholipids containing arachidonic acid. Given the high degree of structural flexibility of this acyl chain this will influence membrane lateral diffusion, and is likely responsible for the transcriptional activation of Lands’ cycle enzymes lpcat3 and mboat7. Of relevance these profound changes in the lipidome were not accompanied by dramatic changes in gene expression in mature differentiated adipocytes, suggesting that adaptive homeostatic mechanisms to ensure partial maintenance of the biophysical properties of membranes likely occur at a post-transcriptional level. PMID:27632198

  2. Stearoyl-CoA desaturase-1 mediated cell apoptosis in colorectal cancer by promoting ceramide synthesis

    PubMed Central

    Chen, Ling; Ren, Jie; Yang, Longhe; Li, Yanting; Fu, Jin; Li, Yuhang; Tian, Yifeng; Qiu, Funan; Liu, Zuguo; Qiu, Yan

    2016-01-01

    Inhibition of stearoyl-CoA desaturase 1 (SCD1) has been found to effectively suppress tumor cell proliferation and induce apoptosis in numerous neoplastic lesions. However, mechanism underlying SCD1-mediated anti-tumor effect has maintained unclear. Herein, we reported endo-lipid messenger ceramides played a critical role in tumor fate modulated by SCD1 inhibition. In vitro study in colorectal cancer cells demonstrated inhibition of SCD1 activity promoted apoptosis attributed to mitochondria dysfunctions, upregulation of reaction oxygen species (ROS), alteration of mitochondrial transmembrane potential and translocation of mitochondrial protein cytochrome C. While these effects were mediated by intracellular ceramide signals through induction of ceramide biosynthesis, rather than exclusive SFA accumulation. In vivo study in xenograft colorectal cancer mice showed pharmacologic administration of SCD1 inhibitor A939 significantly delayed tumor growth, which was reversed by L-cycloserine, an inhibitor of ceramide biosynthesis. These results depicted the cross-talk of SCD1-mediated lipid pathway and endo-ceramide biosynthesis pathway, indicating roles of ceramide signals in SCD1-mediated anti-tumor property. PMID:26813308

  3. Inhibition of dihydroceramide desaturase activity by the sphingosine kinase inhibitor SKI II.

    PubMed

    Cingolani, Francesca; Casasampere, Mireia; Sanllehí, Pol; Casas, Josefina; Bujons, Jordi; Fabrias, Gemma

    2014-08-01

    Sphingosine kinase inhibitor (SKI) II has been reported as a dual inhibitor of sphingosine kinases (SKs) 1 and 2 and has been extensively used to prove the involvement of SKs and sphingosine-1-phosphate (S1P) in cellular processes. Dihydroceramide desaturase (Des1), the last enzyme in the de novo synthesis of ceramide (Cer), regulates the balance between dihydroceramides (dhCers) and Cers. Both SKs and Des1 have interest as therapeutic targets. Here we show that SKI II is a noncompetitive inhibitor (Ki = 0.3 μM) of Des1 activity with effect also in intact cells without modifying Des1 protein levels. Molecular modeling studies support that the SKI II-induced decrease in Des1 activity could result from inhibition of NADH-cytochrome b5 reductase. SKI II, but not the SK1-specific inhibitor PF-543, provoked a remarkable accumulation of dhCers and their metabolites, while both SKI II and PF-543 reduced S1P to almost undetectable levels. SKI II, but not PF543, reduced cell proliferation with accumulation of cells in the G0/G1 phase. SKI II, but not PF543, induced autophagy. These overall findings should be taken into account when using SKI II as a pharmacological tool, as some of the effects attributed to decreased S1P may actually be caused by augmented dhCers and/or their metabolites.

  4. The sphingolipid biosynthetic enzyme Sphingolipid delta8 desaturase is important for chilling resistance of tomato

    PubMed Central

    Zhou, Ying; Zeng, Lanting; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Liao, Yinyin; Deng, Rufang; Xu, Xinlan; Jiang, Yueming; Duan, Xuewu; Baldermann, Susanne; Yang, Ziyin

    2016-01-01

    The physiological functions of sphingolipids in animals have been intensively studied, while less attention has been paid to their roles in plants. Here, we reveal the involvement of sphingolipid delta8 desaturase (SlSLD) in the chilling resistance of tomato (Solanum lycopersicum cv. Micro-Tom). We used the virus-induced gene silencing (VIGS) approach to knock-down SlSLD expression in tomato leaves, and then evaluated chilling resistance. Changes in leaf cell structure under a chilling treatment were observed by transmission electron microscopy. In control plants, SlSLD was highly expressed in the fruit and leaves in response to a chilling treatment. The degree of chilling damage was greater in SlSLD-silenced plants than in control plants, indicating that SlSLD knock-down significantly reduced the chilling resistance of tomato. Compared with control plants, SlSLD-silenced plants showed higher relative electrolytic leakage and malondialdehyde content, and lower superoxide dismutase and peroxidase activities after a chilling treatment. Chilling severely damaged the chloroplasts in SlSLD-silenced plants, resulting in the disruption of chloroplast membranes, swelling of thylakoids, and reduced granal stacking. Together, these results show that SlSLD is crucial for chilling resistance in tomato. PMID:27929095

  5. FADS2 genotype regulates delta-6 desaturase activity and inflammation in human adipose tissue[S

    PubMed Central

    Vaittinen, Maija; Walle, Paula; Kuosmanen, Emmi; Männistö, Ville; Käkelä, Pirjo; Ågren, Jyrki; Schwab, Ursula; Pihlajamäki, Jussi

    2016-01-01

    Obesity is associated with disturbed lipid metabolism and low-grade inflammation in tissues. The aim of this study was to investigate the association between FA metabolism and adipose tissue (AT) inflammation in the Kuopio Obesity Surgery study. We investigated the association of surgery-induced weight loss and FA desaturase (FADS)1/2 genotypes with serum and AT FA profile and with AT inflammation, measured as interleukin (IL)-1β and NFκB pathway gene expression, in order to find potential gene-environment interactions. We demonstrated an association between serum levels of saturated and polyunsaturated n-6 FAs, and estimated enzyme activities of FADS1/2 genes with IL-1β expression in AT both at baseline and at follow-up. Variation in the FADS1/2 genes associated with IL-1β and NFκB pathway gene expression in SAT after weight reduction, but not at baseline. In addition, the FA composition in subcutaneous and visceral fat correlated with serum FAs, and the associations between serum PUFAs and estimated D6D enzyme activity with AT inflammation were also replicated with corresponding AT FAs and AT inflammation. We conclude that the polymorphism in FADS1/2 genes associates with FA metabolism and AT inflammation, leading to an interaction between weight loss and FADS1/2 genes in the regulation of AT inflammation. PMID:26609056

  6. Small-molecule targeting of a diapophytoene desaturase inhibits S. aureus virulence.

    PubMed

    Chen, Feifei; Di, Hongxia; Wang, Youxin; Cao, Qiao; Xu, Bin; Zhang, Xue; Yang, Nana; Liu, Guijie; Yang, Cai-Guang; Xu, Yong; Jiang, Hualiang; Lian, Fulin; Zhang, Naixia; Li, Jian; Lan, Lefu

    2016-03-01

    The surge of antibiotic resistance in Staphylococcus aureus has created a dire need for innovative anti-infective agents that attack new targets, to overcome resistance. In S. aureus, carotenoid pigment is an important virulence factor because it shields the bacterium from host oxidant killing. Here we show that naftifine, a US Food and Drug Administration (FDA)-approved antifungal drug, blocks biosynthesis of carotenoid pigment at nanomolar concentrations. This effect is mediated by competitive inhibition of S. aureus diapophytoene desaturase (CrtN), an essential enzyme for carotenoid pigment synthesis. We found that naftifine attenuated the virulence of a variety of clinical S. aureus isolates, including methicillin-resistant S. aureus (MRSA) strains, in mouse infection models. Specifically, we determined that naftifine is a lead compound for potent CrtN inhibitors. In sum, these findings reveal that naftifine could serve as a chemical probe to manipulate CrtN activity, providing proof of concept that CrtN is a druggable target against S. aureus infections.

  7. Mutations in the maize zeta-carotene desaturase gene lead to viviparous kernel

    PubMed Central

    Chen, Yan; Li, Jiankun; Fan, Kaijian; Du, Yicong; Ren, Zhenjing; Xu, Jing; Zheng, Jun; Liu, Yunjun; Fu, Junjie; Ren, Dongtao

    2017-01-01

    Preharvest sprouting reduces the maize quality and causes a significant yield loss in maize production. vp-wl2 is a Mutator (Mu)-induced viviparous mutant in maize, causing white or pale yellow kernels, dramatically reduced carotenoid and ABA content, and a high level of zeta-carotene accumulation. Here, we reported the cloning of the vp-wl2 gene using a modified digestion-ligation-amplification method (DLA). The results showed that an insertion of Mu9 in the first intron of the zeta-carotene desaturase (ZDS) gene results in the vp-wl2 mutation. Previous studies have suggested that ZDS is likely the structural gene of the viviparous9 (vp9) locus. Therefore, we performed an allelic test using vp-wl2 and three vp9 mutants. The results showed that vp-wl2 is a novel allele of the vp9 locus. In addition, the sequences of ZDS gene were identified in these three vp9 alleles. The vp-wl2 mutant gene was subsequently introgressed into four maize inbred lines, and a viviparous phenotype was observed with yield losses from 7.69% to 13.33%. PMID:28339488

  8. Differential induction of stearoyl-CoA desaturase and acyl-CoA oxidase genes by fibrates in HepG2 cells.

    PubMed

    Rodríguez, C; Cabrero, A; Roglans, N; Adzet, T; Sánchez, R M; Vázquez, M; Ciudad, C J; Laguna, J C

    2001-02-01

    We studied whether two typical effects of fibrates, induction of stearoyl-CoA desaturase (EC 1.14.99.5) and peroxisome proliferation, are related. The effect of bezafibrate on the activity and mRNA of stearoyl-CoA desaturase and acyl-CoA oxidase in the liver and epididymal white adipose tissue of male Sprague-Dawley rats was determined. The same parameters were measured in HepG2 cells, a cell line resistant to peroxisome proliferation, following incubation with ciprofibrate. Bezafibrate increased the hepatic mRNA levels (14.5-fold on day 7) and activity (9.3-fold on day 15) of acyl-CoA oxidase. Stearoyl-CoA desaturase mRNA levels were transiently increased (2.7-fold on day 7), while its activity remained increased at the end of the treatment (2.4-fold). In white adipose tissue, bezafibrate increased the mRNA (5-fold) and activity (1.9-fold) of acyl-CoA oxidase, while stearoyl-CoA desaturase was not modified. Ciprofibrate addition to HepG2 cells cultured in 7% fetal bovine serum (FBS) only increased the stearoyl-CoA desaturase mRNA (1.9-fold). When cells were cultured in 0.5% FBS, ciprofibrate increased acyl-CoA oxidase mRNA (2.2-fold), while the increase in stearoyl-CoA desaturase mRNA was identical (1.9-fold). Further, its activity was also increased (1.5-fold). Incubation of HepG2 cells in the presence of cycloheximide did not alter the capacity of ciprofibrate to induce stearoyl-CoA desaturase mRNA, whereas the presence of actinomycin abolished the induction. In addition, preincubation of HepG2 cells with ciprofibrate increased the rate of stearoyl-CoA desaturase mRNA degradation. The results presented in this study suggest that fibrates induce stearoyl-CoA desaturase activity and mRNA levels independently of peroxisome proliferation.

  9. A defect in the activity of Delta6 and Delta5 desaturases may be a factor predisposing to the development of insulin resistance syndrome.

    PubMed

    Das, Undurti N

    2005-05-01

    GLUT-4 (glucose transporter) receptor, tumor necrosis factor-alpha (TNF-alpha), interleukins-6 (IL-6), daf-genes and PPARs (peroxisomal proliferation activator receptors) play a role in the development of insulin resistance syndrome and associated conditions. But, the exact interaction between these molecules/factors and the mechanism(s) by which they produce insulin resistance syndrome is not clear. I propose that a defect in the activity of the enzymes Delta6 and Delta5 desaturases that are essential for the formation of long chain metabolites of essential fatty acids, linoleic acid and alpha-linolenic acid, is a factor in the development of insulin resistance syndrome. Long chain polyunsaturated fatty acids (LCPUFAs) increase cell membrane fluidity and enhance the number of insulin receptors and the affinity of insulin to its receptors; suppress TNF-alpha, IL-6, macrophage migration inhibitory factor (MIF) and leptin synthesis; increase the number of GLUT-4 receptors, serve as endogenous ligands of PPARs, modify lipolysis, and regulate the balance between pro- and anti-oxidants, and thus, play a critical role in the pathogenesis of insulin resistance. In the nematode, Caenorhabditis elegans, the protein encoded by daf-2 is 35% identical to the human insulin receptor; daf-7 codes a transforming growth factor-beta (TGF-beta) type signal and daf-16 enhances superoxide dismutase (SOD) expression. Melatonin has anti-oxidant actions similar to daf-16, TGF-beta and SOD. Calorie restriction enhances the activity of Delta6 and Delta5 desaturases, melatonin production, decreases daf-2 signaling, free radical generation, and augments anti-oxidant defenses that may explain the beneficial effect of diet control in the management of obesity, insulin resistance, and type II diabetes mellitus. These evidences suggest that the activities of Delta6 and Delta5 enzymes play a critical role in the expression and regulation of GLUT-4, TNF-alpha, IL-6, MIF, daf-genes, melatonin, and

  10. ADS genes for reducing saturated fatty acid levels in seed oils

    DOEpatents

    Heilmann, Ingo H.; Shanklin, John

    2010-02-02

    The present invention relates to enzymes involved in lipid metabolism. In particular, the present invention provides coding sequences for Arabidopsis Desaturases (ADS), the encoded ADS polypeptides, and methods for using the sequences and encoded polypeptides, where such methods include decreasing and increasing saturated fatty acid content in plant seed oils.

  11. ADS genes for reducing saturated fatty acid levels in seed oils

    DOEpatents

    Heilmann, Ingo H; Shanklin, John

    2014-03-18

    The present invention relates to enzymes involved in lipid metabolism. In particular, the present invention provides coding sequences for Arabidopsis Desaturases (ADS), the encoded ADS polypeptides, and methods for using the sequences and encoded polypeptides, where such methods include decreasing and increasing saturated fatty acid content in plant seed oils.

  12. Role of FADS1 and FADS2 polymorphisms in polyunsaturated fatty acid metabolism.

    PubMed

    Glaser, Claudia; Heinrich, Joachim; Koletzko, Berthold

    2010-07-01

    Tissue availability of polyunsaturated fatty acids (PUFAs) depends on dietary intake and metabolic turnover and has a major impact on human health. Strong associations between variants in the human genes fatty acid desaturase 1 (FADS1, encoding Delta-5 desaturase) and fatty acid desaturase 2 (FADS2, encoding Delta-6 desaturase) and blood levels of PUFAs and long-chain PUFAs (LC-PUFAs) have been reported. The most significant associations and the highest proportion of genetically explained variability (28%) were found for arachidonic acid (20:4n-6), the main precursor of eicosanoids. Subjects carrying the minor alleles of several single nucleotide polymorphisms had a lower prevalence of allergic rhinitis and atopic eczema. Therefore, blood levels of PUFAs and LC-PUFAs are influenced not only by diet, but to a large extent also by genetic variants common in a European population. These findings have been replicated in independent populations. Depending on genetic variants, requirements of dietary PUFA or LC-PUFA intakes to achieve comparable biological effects may differ. We recommend including analyses of FADS1 and FADS2 polymorphism in future cohort and intervention studies addressing biological effects of PUFAs and LC-PUFAs.

  13. Characterization of the Fungal Gibberellin Desaturase as a 2-Oxoglutarate-Dependent Dioxygenase and Its Utilization for Enhancing Plant Growth1[W][OA

    PubMed Central

    Bhattacharya, Anjanabha; Kourmpetli, Sofia; Ward, Dennis A.; Thomas, Stephen G.; Gong, Fan; Powers, Stephen J.; Carrera, Esther; Taylor, Benjamin; de Caceres Gonzalez, Francisco Nuñez; Tudzynski, Bettina; Phillips, Andrew L.; Davey, Michael R.; Hedden, Peter

    2012-01-01

    The biosynthesis of gibberellic acid (GA3) by the fungus Fusarium fujikuroi is catalyzed by seven enzymes encoded in a gene cluster. While four of these enzymes are characterized as cytochrome P450 monooxygenases, the nature of a fifth oxidase, GA4 desaturase (DES), is unknown. DES converts GA4 to GA7 by the formation of a carbon-1,2 double bond in the penultimate step of the pathway. Here, we show by expression of the des complementary DNA in Escherichia coli that DES has the characteristics of a 2-oxoglutarate-dependent dioxygenase. Although it has low amino acid sequence homology with known 2-oxoglutarate-dependent dioxygenases, putative iron- and 2-oxoglutarate-binding residues, typical of such enzymes, are apparent in its primary sequence. A survey of sequence databases revealed that homologs of DES are widespread in the ascomycetes, although in most cases the homologs must participate in non-gibberellin (GA) pathways. Expression of des from the cauliflower mosaic virus 35S promoter in the plant species Solanum nigrum, Solanum dulcamara, and Nicotiana sylvestris resulted in substantial growth stimulation, with a 3-fold increase in height in S. dulcamara compared with controls. In S. nigrum, the height increase was accompanied by a 20-fold higher concentration of GA3 in the growing shoots than in controls, although GA1 content was reduced. Expression of des was also shown to partially restore growth in plants dwarfed by ectopic expression of a GA 2-oxidase (GA-deactivating) gene, consistent with GA3 being protected from 2-oxidation. Thus, des has the potential to enable substantial growth increases, with practical implications, for example, in biomass production. PMID:22911627

  14. cDNA cloning and the response to overfeeding in the expression of stearoyl-CoA desaturase 1 gene in Landes goose.

    PubMed

    Zhang, Rui; Zhu, Lihui; Zhang, Yihui; Shao, Dan; Wang, Laidi; Gong, Daoqing

    2013-01-10

    Stearoyl-CoA desaturase 1 (SCD1) is a rate limiting enzyme in the biosynthesis of monounsaturated fatty acids. It has been cloned from several species: Rattus norvegicus, Mus musculus, Homo Sapiens and Gallus gallus, but not from Anser anser. This study was conducted to isolate the SCD1 cDNA sequence and investigate the effect of overfeeding on SCD1 gene tissue expression in Landes goose. The complete cDNA is 3294 bp in length, with an ORF of 1.083 bp encoding a predicted polypeptide of 360 amino acids and 5'/3'-UTR of 74 and 2137 bp, respectively. Quantitative real time PCR (qPCR) was used to examine SCD1 expression in heart, liver, spleen, lung, kidney, gizzard, glandular stomach, intestine, crureus, pectoral muscle, hypothalamus and adipose tissue (abdominal fat) in both the overfed and control group. SCD1 mRNA was highly expressed in goose fatty liver, and the expression levels of SCD1 in liver and fat of overfeeding group were more than double that of the control group. During the overfeeding period, SCD1 expression in liver and adipose tissue reached the highest level after 70 days, but declined at 79 days. In the control group, after fasting 24h, the expression level of SCD1 gene in tissues declined sharply. However, SCD1 gene expression in hypothalamus was unaffected. The results of this study provide a theoretical basis to study the relationship between SCD1 gene expression and the formation of fatty liver of Landes goose in response to overfeeding.

  15. Functional characterization of a Δ5-like fatty acyl desaturase and its expression during early embryogenesis in the noble scallop Chlamys nobilis Reeve.

    PubMed

    Liu, Helu; Guo, Zhicheng; Zheng, Huaiping; Wang, Shuqi; Wang, Yajun; Liu, Wenhua; Zhang, Guofan

    2014-11-01

    Long-chain polyunsaturated fatty acids (LC-PUFAs) are essential in lots of important physiological processes, while, many marine species have no or limited ability of endogenous PUFA biosynthesis, normally due to the lack of key enzymes such as fatty acid desaturase (FAD). In this study, we isolated a scallop Chlamys nobilis cDNA with high homology to vertebrate FADs. Functional characterization in recombinant yeast Saccharomyces cerevisiae showed that scallop FAD exhibited Δ5-desaturation activity towards both saturated and PUFA substrates. Thus, it efficiently desaturated exogenously added PUFA C20:4(n - 3) and C20:3(n - 6) to C20:5(n - 3) (EPA) and C20:4(n - 6) (ARA) respectively. It also converted the yeast's endogenous C18:0 into C18:1(n - 13), and participated in the biosynthesis of non-methylene-interrupted FA by introducing a double bond to C20:3(n - 3) and C20:2(n - 6) in the Δ5 carbon. Temporal transcript profile of scallop FAD was studied during early embryonic development. High level of mRNA was found at the beginning of embryogenesis (egg) and noticeable decreases of were observed during larvae development, suggesting maternal FAD mRNA transfer to the embryo. Further, FAD transcripts were detected in all tissues analyzed, with the gonad and hepatopancreas showing the highest expression.

  16. Complete Genome Sequence of Moraxella osloensis Strain KMC41, a Producer of 4-Methyl-3-Hexenoic Acid, a Major Malodor Compound in Laundry

    PubMed Central

    Hirakawa, Hideki; Morita, Yuji; Tomida, Junko; Sato, Jun; Matsumura, Yuta; Mitani, Asako; Niwano, Yu; Takeuchi, Kohei; Kubota, Hiromi; Kawamura, Yoshiaki

    2016-01-01

    We report the complete genome sequence of Moraxella osloensis strain KMC41, isolated from laundry with malodor. The KMC41 genome comprises a 2,445,556-bp chromosome and three plasmids. A fatty acid desaturase and at least four β-oxidation-related genes putatively associated with 4-methyl-3-hexenoic acid generation were detected in the KMC41 chromosome. PMID:27445387

  17. DAF-16 and Δ9 desaturase genes promote cold tolerance in long-lived Caenorhabditis elegans age-1 mutants.

    PubMed

    Savory, Fiona R; Sait, Steven M; Hope, Ian A

    2011-01-01

    In Caenorhabditis elegans, mutants of the conserved insulin/IGF-1 signalling (IIS) pathway are long-lived and stress resistant due to the altered expression of DAF-16 target genes such as those involved in cellular defence and metabolism. The three Δ(9) desaturase genes, fat-5, fat-6 and fat-7, are included amongst these DAF-16 targets, and it is well established that Δ(9) desaturase enzymes play an important role in survival at low temperatures. However, no assessment of cold tolerance has previously been reported for IIS mutants. We demonstrate that long-lived age-1(hx546) mutants are remarkably resilient to low temperature stress relative to wild type worms, and that this is dependent upon daf-16. We also show that cold tolerance following direct transfer to low temperatures is increased in wild type worms during the facultative, daf-16 dependent, dauer stage. Although the cold tolerant phenotype of age-1(hx546) mutants is predominantly due to the Δ(9) desaturase genes, additional transcriptional targets of DAF-16 are also involved. Surprisingly, survival of wild type adults following a rapid temperature decline is not dependent upon functional daf-16, and cellular distributions of a DAF-16::GFP fusion protein indicate that DAF-16 is not activated during low temperature stress. This suggests that cold-induced physiological defences are not specifically regulated by the IIS pathway and DAF-16, but expression of DAF-16 target genes in IIS mutants and dauers is sufficient to promote cross tolerance to low temperatures in addition to other forms of stress.

  18. Structural and spectroscopic properties of the peroxodiferric intermediate of Ricinus communis soluble Δ9 desaturase.

    PubMed

    Srnec, Martin; Rokob, Tibor András; Schwartz, Jennifer K; Kwak, Yeonju; Rulíšek, Lubomír; Solomon, Edward I

    2012-03-05

    Large-scale quantum and molecular mechanical methods (QM/MM) and QM calculations were carried out on the soluble Δ(9) desaturase (Δ(9)D) to investigate various structural models of the spectroscopically defined peroxodiferric (P) intermediate. This allowed us to formulate a consistent mechanistic picture for the initial stages of the reaction mechanism of Δ(9)D, an important diferrous nonheme iron enzyme that cleaves the C-H bonds in alkane chains resulting in the highly specific insertion of double bonds. The methods (density functional theory (DFT), time-dependent DFT (TD-DFT), QM(DFT)/MM, and TD-DFT with electrostatic embedding) were benchmarked by demonstrating that the known spectroscopic effects and structural perturbation caused by substrate binding to diferrous Δ(9)D can be qualitatively reproduced. We show that structural models whose spectroscopic (absorption, circular dichroism (CD), vibrational and Mössbauer) characteristics correlate best with experimental data for the P intermediate correspond to the μ-1,2-O(2)(2-) binding mode. Coordination of Glu196 to one of the iron centers (Fe(B)) is demonstrated to be flexible, with the monodentate binding providing better agreement with spectroscopic data, and the bidentate structure being slightly favored energetically (1-10 kJ mol(-1)). Further possible structures, containing an additional proton or water molecule are also evaluated in connection with the possible activation of the P intermediate. Specifically, we suggest that protonation of the peroxide moiety, possibly preceded by water binding in the Fe(A) coordination sphere, could be responsible for the conversion of the P intermediate in Δ(9)D into a form capable of hydrogen abstraction. Finally, results are compared with recent findings on the related ribonucleotide reductase and toluene/methane monooxygenase enzymes.

  19. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers.

    PubMed

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou

    2017-02-01

    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem.

  20. Discovery of tumor-specific irreversible inhibitors of stearoyl CoA desaturase | Office of Cancer Genomics

    Cancer.gov

    A hallmark of targeted cancer therapies is selective toxicity among cancer cell lines. We evaluated results from a viability screen of over 200,000 small molecules to identify two chemical series, oxalamides and benzothiazoles, that were selectively toxic at low nanomolar concentrations to the same 4 of 12 human lung cancer cell lines. Sensitive cell lines expressed cytochrome P450 (CYP) 4F11, which metabolized the compounds into irreversible inhibitors of stearoyl CoA desaturase (SCD). SCD is recognized as a promising biological target in cancer and metabolic disease.

  1. [Morphophysiological and biochemical characteristics of potato plants with various expression rates of the Δ12 acyl-lipid desaturase gene].

    PubMed

    Zagoskina, N V; Priadekhina, E V; Lapshin, P V; Iur'eva, N O; Goldenkova-Pavlova, I V

    2014-01-01

    This paper reports on morphophysiological and biochemical characteristics of control and potato plants (Solarium tuberosum L., Skoroplodnyi cultivar) transformed with the Δ12 acyl-lipid desaturase gene (desA) grown long-term in vitro. The transformed plants showed faster growth and faster ontogenesis as compared to controls, which was accompanied with changes in the accumulation of photosynthetic pigments (chlorophylls a and b, carotenoids) and phenolic compounds, including flavonoids in the leaves. These characteristics were pronounced to a high degree in Line II plants with high expression rates of the desA gene, whereas Line I plants (moderate expression rate) were similar to control plants in many parameters.

  2. Chronic Olanzapine Treatment Induces Disorders of Plasma Fatty Acid Profile in Balb/c Mice: A Potential Mechanism for Olanzapine-Induced Insulin Resistance

    PubMed Central

    Xu, Mingzhen; Li, Shihong; Du, Juan; Li, Weiyong; Chen, Hui

    2016-01-01

    Background Atypical antipsychotics such as olanzapine cause metabolic side effects leading to obesity and insulin resistance. The underlying mechanisms remain elusive. In this study we investigated the effects of chronic treatment of olanzapine on the fatty acid composition of plasma in mice. Methods Twenty 8-week female Balb/c mice were randomly assigned to two groups: the OLA group and the control group. After treatment with olanzapine (10 mg/kg/day) or vehicle intraperitoneally for 8 weeks, fasting glucose, insulin levels and oral glucose tolerance test were determined. Effects on plasma fatty acid profile and plasma indices of D5 desaturase, D6 desaturase and SCD1 activity were also investigated. Results Chronic administration of olanzapine significantly elevated fasting glucose and insulin levels, impaired glucose tolerance, but did not increase body weight. Total saturated fatty acids and n-6 polyunsaturated fatty acids were significantly increased and total monounsaturated fatty acids were significantly decreased, while total n-3 polyunsaturated fatty acids showed no prominent changes. Chronic olanzapine treatment significantly up-regulated D6 desaturase activity while down-regulating D5 desaturase activity. Palmitic acid (C16:0), dihomo-γ-linolenic acid (C20:3n-6) and D6 desaturase were associated with an increase probability of insulin resistance, whereas nervonic acid (C24:1) and SCD1 were significantly associated with a lower insulin resistance probability. Conclusions All results indicated that such drug-induced effects on fatty acid profile in plasma were relevant for the metabolic adverse effects associated with olanzapine and possibly other antipsychotics. Further studies are needed to investigate geneticand other mechanisms to explain how plasma fatty acids regulate glucose metabolism and affect the risk of insulin resistance. PMID:27973621

  3. Cloning and expression of stearoyl-CoA desaturase 1 (SCD-1) in the liver of the Sichuan white goose and landes goose responding to overfeeding.

    PubMed

    Pan, Zhi-Xiong; Han, Chun-Chun; Wang, Ji-Wen; Li, Liang; Tang, Hui; Lv, Jia; Lu, Lizhi; Xu, Feng

    2011-06-01

    The EST sequence of goose (Anser cygnoides) Stearoyl-CoA desaturase 1(SCD-1) was obtained from a subtractive cDNA library. To further investigate the role of SCD-1 in lipid metabolism in geese, 5'-RACE and 3'-RACE were carried out in this study to obtain the complete cDNA sequence of goose SCD-1, which contained a 29-bp 5' UTR, a 1074-bp open reading frame (ORF) encoding 357 amino acids, and a 125-bp 3' UTR. The expression of SCD-1 was measured in several tissues, and the effects of overfeeding on the expression of SCD-1 were studied. The results of real time RT-PCR demonstrated that, compared to the brain, goose SCD-1 mRNA was more abundant in the liver. Overfeeding markedly increased the mRNA expression of SCD-1 in the liver of Sichuan White and Landes geese, and gene expression was markedly higher in the Sichuan White goose than in the landes goose. The mRNA abundance of SCD-1 in the liver had significant positive correlations with triacylglycerol (TG) content in liver lipids and in the levels of plasma insulin and very low-density lipoproteins (VLDL) levels in Sichuan white geese. However, the mRNA abundance of SCD-1 in the livers of Landes geese had only significant positive correlations with the TG content in liver lipids. In conclusion, SCD-1 is not only critical for hepatic steatosis in geese but is also important for the difference in lipid deposition in the livers of the two breeds.

  4. Hepatocyte Nuclear Factor 4α (HNF4α) Is a Transcription Factor of Vertebrate Fatty Acyl Desaturase Gene as Identified in Marine Teleost Siganus canaliculatus

    PubMed Central

    Dong, Yewei; Wang, Shuqi; Chen, Junliang; Zhang, Qinghao; Liu, Yang; You, Cuihong; Monroig, Óscar; Tocher, Douglas R.; Li, Yuanyou

    2016-01-01

    Rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the capability of biosynthesizing long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors, and to possess a Δ4 fatty acyl desaturase (Δ4 Fad) which was the first report in vertebrates, and is a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. In order to understand regulatory mechanisms of transcription of Δ4 Fad, the gene promoter was cloned and characterized in the present study. An upstream sequence of 1859 bp from the initiation codon ATG was cloned as the promoter candidate. On the basis of bioinformatic analysis, several binding sites of transcription factors (TF) including GATA binding protein 2 (GATA-2), CCAAT enhancer binding protein (C/EBP), nuclear factor 1 (NF-1), nuclear factor Y (NF-Y), hepatocyte nuclear factor 4α (HNF4α) and sterol regulatory element (SRE), were identified in the promoter by site-directed mutation and functional assays. HNF4α and NF-1 were confirmed to interact with the core promoter of Δ4 Fad by gel shift assay and mass spectrometry. Moreover, over-expression of HNF4α increased promoter activity in HEK 293T cells and mRNA level of Δ4 Fad in rabbitfish primary hepatocytes, respectively. The results indicated that HNF4α is a TF of rabbitfish Δ4 Fad. To our knowledge, this is the first report on promoter structure of a Δ4 Fad, and also the first demonstration of HNF4α as a TF of vertebrate Fad gene involved in transcription regulation of LC-PUFA biosynthesis. PMID:27472219

  5. Using a lipidomics approach for nutritional phenotyping in response to a test meal containing gamma-linolenic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasma fatty acids are derived from preformed sources in the diet and de novo synthesis through the action of desaturase and elongase enzymes. This study was designed to examine the elongation of 18:3n6 into 20:3n6 over an eight-hour period using both targeted gas chromatography–flame ionization det...

  6. Ripening-specific stigmasterol increase in tomato fruit is associated with increased sterol 22-desaturase (CYP710A7) gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytosterol content and composition and sterol 22-desaturase (LeSD1; CYP710A7) transcript levels in pericarp tissue of 'Rutgers' tomato fruit were compared in the wild-type (wt) and isogenic lines of the non-ripening mutants nor and rin at four stages of ripening/aging. Fruit of wt were harvested at...

  7. Diversification of substrate specificities in teleostei Fads2: characterization of Δ4 and Δ6Δ5 desaturases of Chirostoma estor[S

    PubMed Central

    Fonseca-Madrigal, Jorge; Navarro, Juan C.; Hontoria, Francisco; Tocher, Douglas R.; Martínez-Palacios, Carlos A.; Monroig, Óscar

    2014-01-01

    Currently existing data show that the capability for long-chain PUFA (LC-PUFA) biosynthesis in teleost fish is more diverse than in other vertebrates. Such diversity has been primarily linked to the subfunctionalization that teleostei fatty acyl desaturase (Fads)2 desaturases have undergone during evolution. We previously showed that Chirostoma estor, one of the few representatives of freshwater atherinopsids, had the ability for LC-PUFA biosynthesis from C18 PUFA precursors, in agreement with this species having unusually high contents of DHA. The particular ancestry and pattern of LC-PUFA biosynthesis activity of C. estor make this species an excellent model for study to gain further insight into LC-PUFA biosynthetic abilities among teleosts. The present study aimed to characterize cDNA sequences encoding fatty acyl elongases and desaturases, key genes involved in the LC-PUFA biosynthesis. Results show that C. estor expresses an elongase of very long-chain FA (Elovl)5 elongase and two Fads2 desaturases displaying Δ4 and Δ6/Δ5 specificities, thus allowing us to conclude that these three genes cover all the enzymatic abilities required for LC-PUFA biosynthesis from C18 PUFA. In addition, the specificities of the C. estor Fads2 enabled us to propose potential evolutionary patterns and mechanisms for subfunctionalization of Fads2 among fish lineages. PMID:24792929

  8. Citrus flavonoids repress the mRNA for stearoyl-CoA desaturase, a key enzyme in lipid synthesis and obesity control, in rat primary hepatocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus flavonoids have been shown to decrease plasma lipid levels, improve glucose tolerance, and attenuate obesity. One possible mechanism underlying these physiological effects is reduction of hepatic levels of the mRNA for stearoyl CoA desaturase-1 (SCD1), since repression of this enzyme reduces ...

  9. Cheese can reduce indexes that estimate fatty acid desaturation. Results from the Oslo Health Study and from experiments with human hepatoma cells.

    PubMed

    Høstmark, Arne T; Lunde, Marianne S H

    2012-02-01

    Previously, cheese intake was shown to be inversely related to serum triglycerides, raising the possibility that cheese might inhibit triglyceride synthesis, which is governed by fatty acid desaturases. Therefore, analyses were done to study whether cheese intake was associated with indexes that reflect fatty acid desaturation in 121 healthy ethnic Norwegians aged 40-45 years, a subsample from the Oslo Health Study (N = 18 777). Experiments with human hepatoma cells (HepG2) were done to clarify whether cheese might have a causal effect on desaturases. Fatty acid distribution in lipids of human sera and HepG2 cells was determined by gas chromatography. Δ9-Desaturase was estimated by the (16:1,n-7)/(16:0) and (18:1,n-9)/(18:0) ratios, abbreviated ds9_1 and ds9_2, and Δ5-desaturase (ds5) by the (20:4,n-6)/(18:2,n-6) ratio. Correlation, ANOVA, and multiple linear regression models were used to study associations. Oslo Health Study: Subjects with cheese intake >4-6 times per week had 33% lower ds9_1 and 16% lower ds5 than subjects with intake ≤ 4-6 times per week. The cheese intake vs. ds5 association prevailed when adjusting for sex, time since last meal, fatty fish, vegetables, fruit-berries, fruit juice, cod liver oil, coffee, alcohol, body mass index, physical activity, length of education, and smoking. HepG2 cells: An ethanol extract of Jarlsberg cheese lowered the desaturase indexes. Inhibition of ds9_1 increased with increasing amount cheese extract added. Thus, cheese may contain inhibitors of desaturases, thereby providing an explanation for the previously reported negative association between cheese intake and triglycerides.

  10. Agronomic effects of mutations in two soybean Stearoyl-ACP-Desaturases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] oil normally contains 2-4% stearic acid. Oil with higher levels of stearic acid is desired for use in the baking industry, for both its chemical properties and human health benefits. Several lines with increased stearic acid have been identified; however, the agronom...

  11. Synthesis of docosahexaenoic acid from eicosapentaenoic acid in retina neurons protects photoreceptors from oxidative stress.

    PubMed

    Simón, María Victoria; Agnolazza, Daniela L; German, Olga Lorena; Garelli, Andrés; Politi, Luis E; Agbaga, Martin-Paul; Anderson, Robert E; Rotstein, Nora P

    2016-03-01

    Oxidative stress is involved in activating photoreceptor death in several retinal degenerations. Docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in the retina, protects cultured retina photoreceptors from apoptosis induced by oxidative stress and promotes photoreceptor differentiation. Here, we investigated whether eicosapentaenoic acid (EPA), a metabolic precursor to DHA, had similar effects and whether retinal neurons could metabolize EPA to DHA. Adding EPA to rat retina neuronal cultures increased opsin expression and protected photoreceptors from apoptosis induced by the oxidants paraquat and hydrogen peroxide (H2 O2 ). Palmitic, oleic, and arachidonic acids had no protective effect, showing the specificity for DHA. We found that EPA supplementation significantly increased DHA percentage in retinal neurons, but not EPA percentage. Photoreceptors and glial cells expressed Δ6 desaturase (FADS2), which introduces the last double bond in DHA biosynthetic pathway. Pre-treatment of neuronal cultures with CP-24879 hydrochloride, a Δ5/Δ6 desaturase inhibitor, prevented EPA-induced increase in DHA percentage and completely blocked EPA protection and its effect on photoreceptor differentiation. These results suggest that EPA promoted photoreceptor differentiation and rescued photoreceptors from oxidative stress-induced apoptosis through its elongation and desaturation to DHA. Our data show, for the first time, that isolated retinal neurons can synthesize DHA in culture. Docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in retina photoreceptors, and its precursor, eicosapentaenoic acid (EPA) have multiple beneficial effects. Here, we show that retina neurons in vitro express the desaturase FADS2 and can synthesize DHA from EPA. Moreover, addition of EPA to these cultures protects photoreceptors from oxidative stress and promotes their differentiation through its metabolization to DHA.

  12. High Expression of Stearoyl-CoA Desaturase 1 Predicts Poor Prognosis in Patients with Clear-Cell Renal Cell Carcinoma

    PubMed Central

    Zou, Yun; Kong, Wen; Dong, Baijun; Huang, Jiwei; Chen, Yonghui; Xue, Wei; Huang, Yiran; Zhang, Jin

    2016-01-01

    Stearoyl-CoA desaturase 1 (SCD1), the rate-limiting enzymes in the biosynthesis of monounsaturated fatty acids from saturated fatty acids, have been gradually recognized as a potential therapeutic target for various malignancies, particularly in clear-cell renal cell carcinoma (ccRCC). However, the prognostic value of SCD1 in ccRCC is still unknown. The aim of this study is to evaluate the clinical significance of SCD1 expression in patients with ccRCC. SCD1 expression in tumor tissues obtained from 359 patients who underwent nephrectomy for ccRCC are retrospectively assessed. During a median follow-up of 63 months (range: 1–144month), 56 patients in total died before the last follow-up in this study. Survival curves were plotted with the Kaplan–Meier method and compared with the log-rank test. Meanwhile, univariate and multivariate Cox regression models were applied to evaluate the prognostic value of SCD1 expression in overall survival (OS) for ccRCC patients. Moreover, SCD1 was enrolled into a newly built nomogram with factors selected by multivariate analysis, and the calibration was built to evaluate the predictive accuracy of nomogram. High SCD1 expression occurred in 61.6% (221/359) of ccRCC patients, which was significantly associated with age (p = 0.030), TNM stage (p = 0.021), pN stage (p = 0.014), Fuhrman grade (p = 0.014) and tumor sizes (p = 0.040). In multivariate analysis, SCD1 expression was confirmed as an adverse independent prognostic factor for OS. The prognostic accuracy of TNM stage, Fuhrman grade and tumor sizes was significantly increased when SCD1 expression was added. The independent prognostic factors, pT stage, pN stage, Fuhrman grade and tumor sizes, as well as SCD1 expression were integrated to establish a predictive nomogram with high predictive accuracy. Calibration curves revealed optimal consistency between observations and prognosis. In conclusion, high SCD1 expression is an independent prognostic factor for OS in patients

  13. [Blood deficiency values of polyunsaturated fatty acids of phospholipids, vitamin E and glutathione peroxidase as possible risk factors in the onset and development of acquired immunodeficiency syndrome].

    PubMed

    Passi, S; De Luca, C; Picardo, M; Morrone, A; Ippolito, F

    1990-04-01

    Plasma levels of vitamin E (vit E) and polyunsatured fatty acids of phospholipids (PUFA-PL) as well as erythrocyte glutathione peroxidase (GSH-Px) activity are significantly lower (p less than 0.001) in patients HIV sero-positive (AIDS and ARC cases) both affected and not affected with seborrheic dermatitis and in 32% of HIV sero-negative intravenous drug abusers (IVDA, A subgroup) than in controls. The deficiency of PUFA-PL (mainly C20:3 n-6, C20:4 n-6 and C22:6 n-3) which is associated with a significant increase (p less than 0.001) of saturated palmitic and stearic acids and monounsaturated oleic acid, cannot be correlated to an active lipoperoxidative process. In fact the levels of thiobarbituric acid-reactive materials (TBA-RM) are not increased in the plasma of HIV sero-positive patients and A subgroup of IVDA. It is likely that the reduction of PUFA-PL is due to an inhibition of hepatic microsomal desaturase enzymes (delta 6 desaturase, delta 5 desaturase, delta 4 desaturase) which are involved in both n-6 and n-3 pathways. Since IVDA represent, and not only in Italy, a major risk category for HIV infection, we suggest that reduced blood levels of vit E, GSH-Px and particularly PUFA-PL may be added to the list of risk factors favouring the onset and the development of AIDS.

  14. Glucomannan- and glucomannan plus spirulina-enriched pork affect liver fatty acid profile, LDL receptor expression and antioxidant status in Zucker fa/fa rats fed atherogenic diets

    PubMed Central

    González-Torres, Laura; Matos, Cátia; Vázquez-Velasco, Miguel; Santos-López, Jorge A.; Sánchez-Martínez, Iria; García–Fernández, Camino; Bastida, Sara; Benedí, Juana; Sánchez-Muniz, Francisco J.

    2017-01-01

    ABSTRACT We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP) on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC (cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alpha-linolenic ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS, decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia. Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding on the liver fatty acid and antioxidant statuses. PMID:28325998

  15. Desaturation and chain elongation of essential fatty acids in isolated liver cells from rat and rainbow trout

    SciTech Connect

    Hagve, T.A.; Christophersen, B.O.; Dannevig, B.H.

    1986-03-01

    Isolated hepatocytes from rainbow trout and rat were incubated with /sup 14/C-labeled linoleic acid, linolenic acid, dihomogammalinolenic acid or eicosapentaenoic acid. The most striking difference in the desaturase activity was the lower level of delta 5 desaturase in trout than in rat. No delta 4 desaturation of 22:4(n-6) to 22:5(n-6) was observed in either of the two species, while the conversion of 22:5(n-3) to 22:6(n-3) was significant in both groups and highest in rainbow trout. The chain-elongating activity was remarkably similar in the two species, except for the dead-end elongation which was distinctly more important in fish.

  16. Probing fatty acid metabolism in bacteria, cyanobacteria, green microalgae and diatoms with natural and unnatural fatty acids.

    PubMed

    Beld, Joris; Abbriano, Raffaela; Finzel, Kara; Hildebrand, Mark; Burkart, Michael D

    2016-04-01

    In both eukaryotes and prokaryotes, fatty acid synthases are responsible for the biosynthesis of fatty acids in an iterative process, extending the fatty acid by two carbon units every cycle. Thus, odd numbered fatty acids are rarely found in nature. We tested whether representatives of diverse microbial phyla have the ability to incorporate odd-chain fatty acids as substrates for their fatty acid synthases and their downstream enzymes. We fed various odd and short chain fatty acids to the bacterium Escherichia coli, cyanobacterium Synechocystis sp. PCC 6803, green microalga Chlamydomonas reinhardtii and diatom Thalassiosira pseudonana. Major differences were observed, specifically in the ability among species to incorporate and elongate short chain fatty acids. We demonstrate that E. coli, C. reinhardtii, and T. pseudonana can produce longer fatty acid products from short chain precursors (C3 and C5), while Synechocystis sp. PCC 6803 lacks this ability. However, Synechocystis can incorporate and elongate longer chain fatty acids due to acyl-acyl carrier protein synthetase (AasS) activity, and knockout of this protein eliminates the ability to incorporate these fatty acids. In addition, expression of a characterized AasS from Vibrio harveyii confers a similar capability to E. coli. The ability to desaturate exogenously added fatty acids was only observed in Synechocystis and C. reinhardtii. We further probed fatty acid metabolism of these organisms by feeding desaturase inhibitors to test the specificity of long-chain fatty acid desaturases. In particular, supplementation with thia fatty acids can alter fatty acid profiles based on the location of the sulfur in the chain. We show that coupling sensitive gas chromatography mass spectrometry to supplementation of unnatural fatty acids can reveal major differences between fatty acid metabolism in various organisms. Often unnatural fatty acids have antibacterial or even therapeutic properties. Feeding of short

  17. Long-term fructose consumption prolongs hepatic stearoyl-CoA desaturase 1 activity independent of upstream regulation in rats.

    PubMed

    Liu, Li; Wang, Shang; Yao, Ling; Li, Jin-Xiu; Ma, Peng; Jiang, Li-Rong; Ke, Da-Zhi; Pan, Yong-Quan; Wang, Jian-Wei

    2016-10-28

    Dietary fructose is considered a risk factor for metabolic disorders, such as fatty liver disease. However, the mechanism underlying the effects of fructose is not well characterized. We investigated the hepatic expression of key regulatory genes related to lipid metabolism following fructose feeding under well-defined conditions. Rats were fed standard chow supplemented with 10% w/v fructose solution for 5 weeks, and killed after chow-fasting and fructose withdrawal (fasting) or chow-fasting and continued fructose (fructose alone) for 14 h. Hepatic deposition of triglycerides was found in rats from both groups. As expected, fructose alone increased mRNA levels of lipogenesis-related genes and correspondingly decreased mRNA levels of lipid oxidative genes in the liver. Interesting, hepatic levels of stearoyl-CoA desaturase (SCD)1 mRNA remained elevated under fructose withdrawn conditions, although expression levels of other genes, including two key transcription factors (carbohydrate response element binding protein (ChREBP) and sterol regulatory element-binding protein (SREBP)-1c) fell to normal levels, indicating that long-term fructose intake increased SCD1 activity, independent of upstream regulatory genes, such as ChREBP and SREBP-1c. In conclusion, SCD1 overexpression in fatty liver disease is not affected by fasting after long-term fructose consumption in rats. Regulation of SCD1 plays an important role in fructose-induced hepatic steatosis.

  18. Transcript levels of phytoene desaturase gene in Dunaliella salina Teod. as affected by PbS nanoparticles and light intensity

    PubMed Central

    Zamani, Hajar; Moradshahi, Ali

    2016-01-01

    Phytoene synthase (Psy) and Phytoene desaturase (Pds) are the first two regulatory enzymes in the carotenoids biosynthetic pathway. The genes Psy and Pds are under transcriptional control in many photosynthetic organisms. In the present study, using quantitative real time- PCR (qRT-PCR), the effects of uncoated and gum-Arabic coated PbS nanoparticles (GA-coated PbS NPs) and light intensity on the mRNA levels of Pds were investigated. Relative to mRNA level of Pds at 100 µmol photon m-2 s-1 light intensity (control culture), 2.2-fold increase in transcript levels occurred after 12 h of exposure to higher light intensity, which is significantly (P<0.05) different compared to control. After 48 h of exposure, the mRNA level of Pds was reduced to that in control. This indicates that light intensity regulates Pds at the mRNA level. In the presence of uncoated and GA-coated PbS NPs, the transcript levels of Pds were decreased over time, with uncoated PbS NPs having more inhibitory effects on mRNA levels compared to GA- coated PbS NPs. This shows that PbS NPs have adverse effects on transcription or post transcriptional processing and coating nanoparticles with biopolymers reduces their toxicity to organisms. Being under control, it seems that genetic manipulation of Pds may result in increased biotechnological production of carotenoids by D. salina. PMID:28097172

  19. Dihydroceramide Desaturase Knockdown Impacts Sphingolipids and Apoptosis after Photodamage in Human Head and Neck Squamous Carcinoma Cells

    PubMed Central

    BREEN, PAUL; JOSEPH, NICHOLAS; THOMPSON, KYLE; KRAVEKA, JACQUELINE M.; GUDZ, TATYANA I.; LI, LI; RAHMANIYAN, MEHRDAD; BIELAWSKI, JACEK; PIERCE, JASON S.; VAN BUREN, ERIC; BHATTI, GAURAV; SEPAROVIC, DUSKA

    2014-01-01

    Background Dihydroceramide desaturase 1 (DES) is the enzyme responsible for converting dihydroceramide into ceramide in the de novo sphingolipid biosynthesis pathway. Dihydroceramide can inhibit ceramide channel formation to interfere with apoptosis. We have shown that following ceramide synthase knockdown, photodynamic therapy (PDT), a cancer treatment modality, is associated with decreased levels of ceramides and dihydroceramides in cells that are resistant to apoptosis. Aim Here we investigated the effect of DES knockdown on the sphingolipid profile and apoptosis in human head and neck squamous carcinoma cells after PDT with the silicon phthalocyanine Pc 4. Materials and Methods Following siRNA transfection and PDT treatment, quantitative real-time polymerase chain reaction for quantification of DES mRNA, immunoblotting for protein expression, mass spectrometry for sphingolipid analysis, spectrofluorometry for caspase 3-like (DEVDase) activity, flow cytometry for apoptosis detection, and trypan blue assay for cell viability evaluation, were performed. Results Down-regulation of DES led to a substantial increase in levels of dihydroceramides without affecting ceramide levels. PDT-induced accumulation of individual dihydroceramides and global ceramides was increased by DES knockdown. Concomitantly, mitochondrial depolarization, DEVDase activation, late-apoptosis and cell death were attenuated by DES knockdown. Early apoptosis, however, was enhanced. Conclusion Our findings support the following: (i) dihydroceramide reduces pro-apoptotic effects of ceramide; (ii) cells adapt to DES knockdown to become more sensitive to ceramide and early-apoptosis; (iii) DES is a potential molecular target for regulating apoptotic resistance to PDT. PMID:23267130

  20. Construction of a cyanobacterium synthesizing cyclopropane fatty acids.

    PubMed

    Machida, Shuntaro; Shiraiwa, Yoshihiro; Suzuki, Iwane

    2016-09-01

    Microalgae have received much attention as a next-generation source of biomass energy. However, most of the fatty acids (FAs) from microalgae are multiply unsaturated; thus, the biofuels derived from them are fluid, but vulnerable to oxidation. In this study, we attempted to synthesize cyclopropane FAs in the cyanobacterium Synechocystis sp. PCC 6803 by expressing the cfa gene for cyclopropane FA synthase from Escherichia coli with the aim of producing FAs that are fluid and stable in response to oxidization. We successfully synthesized cyclopropane FAs in Synechocystis with a yield of ~30% of total FAs. Growth of the transformants was altered, particularly at low temperatures, but photosynthesis and respiration were not significantly affected. C16:1(∆9) synthesis in the desA(-)/desD(-) strain by expression of the desC2 gene for sn-2 specific ∆9 desaturase positively affected growth at low temperatures via promotion of various cellular processes, with the exceptions of photosynthesis and respiration. Estimation of the apparent activities of desaturases suggested that some acyl-lipid desaturases might recognize the lipid side chain.

  1. Synthesis of docosahexaenoic acid from eicosapentaenoic acid in retina neurons protects photoreceptors from oxidative stress

    PubMed Central

    Simón, María Victoria; Agnolazza, Daniela L.; German, Olga Lorena; Garelli, Andrés; Politi, Luis E.; Agbaga, Martin-Paul; Anderson, Robert E.; Rotstein, Nora P.

    2015-01-01

    Oxidative stress is involved in activating photoreceptor death in several retinal degenerations. Docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in the retina, protects cultured retina photoreceptors from apoptosis induced by oxidative stress and promotes photoreceptor differentiation. Here we investigated whether eicosapentaenoic acid (EPA), a metabolic precursor to DHA, had similar effects and whether retinal neurons could metabolize EPA to DHA. Adding EPA to rat retina neuronal cultures increased opsin expression and protected photoreceptors from apoptosis induced by the oxidants paraquat (PQ) and hydrogen peroxide (H2O2). Palmitic, oleic, and arachidonic acids had no protective effect, showing the specificity for DHA. We found that EPA supplementation significantly increased DHA percentage in retinal neurons, but not EPA percentage. Photoreceptors and glial cells expressed Δ6 desaturase (FADS2), which introduces the last double bond in DHA biosynthetic pathway. Pre-treatment of neuronal cultures with CP-24879 hydrochloride, a Δ5/Δ6 desaturase inhibitor, prevented EPA-induced increase in DHA percentage and completely blocked EPA protection and its effect on photoreceptor differentiation. These results suggest that EPA promoted photoreceptor differentiation and rescued photoreceptors from oxidative stress-induced apoptosis through its elongation and desaturation to DHA. Our data show, for the first time, that isolated retinal neurons can synthesize DHA in culture. PMID:26662863

  2. Indole-3-acetic acid (IAA) induced changes in oil content, fatty acid profiles and expression of four fatty acid biosynthetic genes in Chlorella vulgaris at early stationary growth phase.

    PubMed

    Jusoh, Malinna; Loh, Saw Hong; Chuah, Tse Seng; Aziz, Ahmad; Cha, Thye San

    2015-03-01

    Microalgae lipids and oils are potential candidates for renewable biodiesel. Many microalgae species accumulate a substantial amount of lipids and oils under environmental stresses. However, low growth rate under these adverse conditions account for the decrease in overall biomass productivity which directly influence the oil yield. This study was undertaken to investigate the effect of exogenously added auxin (indole-3-acetic acid; IAA) on the oil content, fatty acid compositions, and the expression of fatty acid biosynthetic genes in Chlorella vulgaris (UMT-M1). Auxin has been shown to regulate growth and metabolite production of several microalgae. Results showed that oil accumulation was highest on days after treatment (DAT)-2 with enriched levels of palmitic (C16:0) and stearic (C18:0) acids, while the linoleic (C18:2) and α-linolenic (C18:3n3) acids levels were markedly reduced by IAA. The elevated levels of saturated fatty acids (C16:0 and C18:0) were consistent with high expression of the β-ketoacyl ACP synthase I (KAS I) gene, while low expression of omega-6 fatty acid desaturase (ω-6 FAD) gene was consistent with low production of C18:2. However, the increment of stearoyl-ACP desaturase (SAD) gene expression upon IAA induction did not coincide with oleic acid (C18:1) production. The expression of omega-3 fatty acid desaturase (ω-3 FAD) gene showed a positive correlation with the synthesis of PUFA and C18:3n3.

  3. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers1[OPEN

    PubMed Central

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K.; Dyer, John M.; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Jenks, Matthew A.

    2017-01-01

    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4’s principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation’s effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. PMID:28069670

  4. Sequence-level comparative analysis of the Brassica napus genome around two stearoyl-ACP desaturase loci.

    PubMed

    Cho, Kwangsoo; O'Neill, Carmel M; Kwon, Soo-Jin; Yang, Tae-Jin; Smooker, Andrew M; Fraser, Fiona; Bancroft, Ian

    2010-02-01

    We conducted a sequence-level comparative analyses, at the scale of complete bacterial artificial chromosome (BAC) clones, between the genome of the most economically important Brassica species, Brassica napus (oilseed rape), and those of Brassica rapa, the genome of which is currently being sequenced, and Arabidopsis thaliana. We constructed a new B. napus BAC library and identified and sequenced clones that contain homoeologous regions of the genome including stearoyl-ACP desaturase-encoding genes. We sequenced the orthologous region of the genome of B. rapa and conducted comparative analyses between the Brassica sequences and those of the orthologous region of the genome of A. thaliana. The proportion of genes conserved (approximately 56%) is lower than has been reported previously between A. thaliana and Brassica (approximately 66%). The gene models for sets of conserved genes were used to determine the extent of nucleotide conservation of coding regions. This was found to be 84.2 +/- 3.9% and 85.8 +/- 3.7% between the B. napus A and C genomes, respectively, and that of A. thaliana, which is consistent with previous results for other Brassica species, and 97.5 +/- 3.1% between the B. napus A genome and B. rapa, and 93.1 +/- 4.9% between the B. napus C genome and B. rapa. The divergence of the B. napus genes from the A genome and the B. rapa genes was greater than anticipated and indicates that the A genome ancestor of the B. napus cultivar studied was relatively distantly related to the cultivar of B. rapa selected for genome sequencing.

  5. Changes in the Enzymes for Fatty Acid Synthesis and Desaturation during Acclimation of Developing Soybean Seeds to Altered Growth Temperature

    PubMed Central

    Cheesbrough, Thomas M.

    1989-01-01

    Temperature-induced changes in the enzymes for fatty acid synthesis and desaturation were studied in developing soybean seeds (Glycine max L. var Williams 82). Changes were induced by culture of the seed pods for 20 hours in liquid media at 20, 25, or 35°C. Linoleoyl and oleoyl desaturases were 94 and 10 times as active, respectively, in seeds cultured at 20°C as those cultured at 25°C. Both desaturases had negligible activity in seeds cultured at 35°C compared to seeds cultured at 20°C. Though less dramatic, other enzymes also showed differences in activity after 20 hours in culture at 20, 25, or 35°C. Stearoyl-acyl carrier protein (ACP) desaturase and CDP-choline:diacylglycerol phosphorylcholine transferase were most active in preparations from 20°C cultures. Activities were twofold lower at 25°C and a further threefold lower in 35°C cultures. Cultures from 25 and 35°C had 60 and 40%, respectively, of the phosphorylcholine:CTP cytidylyl transferase activity present in cultures grown at 20°C. Fatty acid synthetase, malonyl-coenzyme A:ACP transacylase, palmitoyl-ACP elongation, and choline kinase were not significantly altered by culture temperature. These data suggest that the enzymes for fatty acid desaturation and phosphatidylcholine synthesis can be rapidly modulated in response to altered growth temperatures, while the enzymes for fatty acid synthesis and elongation are not. PMID:16666840

  6. High level accumulation of gamma linolenic acid (C18:3Δ6.9,12 cis) in transgenic safflower (Carthamus tinctorius) seeds.

    PubMed

    Nykiforuk, Cory L; Shewmaker, Christine; Harry, Indra; Yurchenko, Olga P; Zhang, Mei; Reed, Catherine; Oinam, Gunamani S; Zaplachinski, Steve; Fidantsef, Ana; Boothe, Joseph G; Moloney, Maurice M

    2012-04-01

    Gamma linolenic acid (GLA; C18:3Δ6,9,12 cis), also known as γ-Linolenic acid, is an important essential fatty acid precursor for the synthesis of very long chain polyunsaturated fatty acids and important pathways involved in human health. GLA is synthesized from linoleic acid (LA; C18:2Δ9,12 cis) by endoplasmic reticulum associated Δ6-desaturase activity. Currently sources of GLA are limited to a small number of plant species with poor agronomic properties, and therefore an economical and abundant commercial source of GLA in an existing crop is highly desirable. To this end, the seed oil of a high LA cultivated species of safflower (Carthamus tinctorius) was modified by transformation with Δ6-desaturase from Saprolegnia diclina resulting in levels exceeding 70% (v/v) of GLA. Levels around 50% (v/v) of GLA in seed oil was achieved when Δ12-/Δ6-desaturases from Mortierella alpina was over-expressed in safflower cultivars with either a high LA or high oleic (OA; C18:1Δ9 cis) background. The differences in the overall levels of GLA suggest the accumulation of the novel fatty acid was not limited by a lack of incorporation into the triacylgylcerol backbone (>66% GLA achieved), or correlated with gene dosage (GLA levels independent of gene copy number), but rather reflected the differences in Δ6-desaturase activity from the two sources. To date, these represent the highest accumulation levels of a newly introduced fatty acid in a transgenic crop. Events from these studies have been propagated and recently received FDA approval for commercialization as Sonova™400.

  7. Induction of Lipid and Oleosin Biosynthesis by (+)-Abscisic Acid and Its Metabolites in Microspore-Derived Embryos of Brassica napus L.cv Reston (Biological Responses in the Presence of 8[prime]-Hydroxyabscisic Acid).

    PubMed Central

    Zou, J.; Abrams, G. D.; Barton, D. L.; Taylor, D. C.; Pomeroy, M. K.; Abrams, S. R.

    1995-01-01

    Microspore-derived (MD) embryos of Brassica napus L. cv Reston were used to test the effects of (+)-abscisic acid ([(+)-ABA]) and its metabolites, 8[prime]-hydroxyabscisic acid (8[prime]-OH ABA) and (-)-phaseic acid (PA), on the accumulation of very long-chain monounsaturated fatty acids (VLCMFAs) and induction of genes encoding a 19-kD oleosin protein and a [delta]15 desaturase during embryogenesis. Developing early to mid-cotyledonary MD embryos at 16 to 19 d in culture were treated with 10 [mu]M hormone/metabolite for 4 d. At various times during incubation, embryos and medium were analyzed to determine levels of hormone/metabolite, VLCMFAs, and oleosin or [delta]15 desaturase transcripts. The VLCMFAs, 20:1 and 22:1, primarily in triacylglycerols, increased by 200% after 72 h in the presence of (+)-ABA and 8[prime]-OH ABA relative to the control. In contrast, treatment with PA for 72 h had little effect (20% increase) on the level of VLCMFAs. The first 24 to 72 h of (+)-ABA treatment were critical in the induction of VLCMFA biosynthesis, with 8[prime]-OH ABA lagging slightly behind (+)-ABA in promoting this response. The accumulation of VLCMFAs was positively correlated with an increase in elongase activity. (+)-ABA and its 8[prime]-OH ABA metabolite induced the accumulation of a 19-kD oleosin transcript within 2 to 4 h in culture. In addition, both (+)-ABA and 8[prime]-OH ABA induced the same level of [delta]15 desaturase transcript by 8 h. PA had no effect on the induction of either oleosin or [delta]15 desaturase transcripts. To our knowledge, this is the first report of the biological activity of 8[prime]-OH ABA and of stimulatory effects of (+)-ABA and 8[prime]-OH ABA on lipid and oleosin biosynthesis. PMID:12228493

  8. Accumulation of ricinoleic, lesquerolic, and densipolic acids in seeds of transgenic Arabidopsis plants that express a fatty acyl hydroxylase cDNA from castor bean.

    PubMed Central

    Broun, P; Somerville, C

    1997-01-01

    A cDNA encoding the oleate 12-hydroxylase from castor bean (Ricinus communis L.) has previously been shown to direct the synthesis of small amounts of ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) in seeds of transgenic tobacco plants. Expression of the cDNA under control of the Brassica napus napin promoter in transgenic Arabidopsis thaliana plants resulted in the accumulation of up to 17% of seed fatty acids as ricinoleate and two novel fatty acids that have been identified by gas chromatography-mass spectrometry as lesquerolic (14-hydroxyeicos-cis-11-enoic acid) and densipolic (12-hydroxyoctadec-cis-9,15-dienoic acid) acids. Traces of auricolic acid were also observed. These results suggest that either the castor hydroxylase can utilize oleic acid and eicosenoic acid as substrates for ricinoleic and lesquerolic acid biosynthesis, respectively, or Arabidopsis contains an elongase that accepts ricinoleic acid as a substrate. These observations are also consistent with indirect biochemical evidence that an n-3 desaturase is capable of converting ricinoleic acid to densipolic acid. Expression of the castor hydroxylase also caused enhanced accumulation of oleic acid and a corresponding decrease in the levels of polyunsaturated fatty acids. Since the steady-state level of mRNA for the oleate-12 desaturase was not affected, it appears that the presence of the hydroxylase, directly or indirectly, causes posttranscriptional inhibition of desaturation. PMID:9085577

  9. Effect of dietary n-3 fatty acids supplementation on fatty acid metabolism in atorvastatin-administered SHR.Cg-Lepr(cp)/NDmcr rats, a metabolic syndrome model.

    PubMed

    Al Mamun, Abdullah; Hashimoto, Michio; Katakura, Masanori; Tanabe, Yoko; Tsuchikura, Satoru; Hossain, Shahdat; Shido, Osamu

    2017-01-01

    The effects of cholesterol-lowering statins, which substantially benefit future cardiovascular events, on fatty acid metabolism have remained largely obscured. In this study, we investigated the effects of atorvastatin on fatty acid metabolism together with the effects of TAK-085 containing highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl ester on atorvastatin-induced n-3 polyunsaturated fatty acid lowering in SHR.Cg-Lepr(cp)/NDmcr (SHRcp) rats, as a metabolic syndrome model. Supplementation with 10mg/kg body weight/day of atorvastatin for 17 weeks significantly decreased plasma total cholesterol and very low density lipoprotein cholesterol. Atorvastatin alone caused a subtle change in fatty acid composition particularly of EPA and DHA in the plasma, liver or erythrocyte membranes. However, the TAK-085 consistently increased both the levels of EPA and DHA in the plasma, liver and erythrocyte membranes. After confirming the reduction of plasma total cholesterol, 300mg/kg body weight/day of TAK-085 was continuously administered for another 6 weeks. Supplementation with TAK-085 did not decrease plasma total cholesterol but significantly increased the EPA and DHA levels in both the plasma and liver compared with rats administered atorvastatin only. Supplementation with atorvastatin alone significantly decreased sterol regulatory element-binding protein-1c, Δ5- and Δ6-desaturases, elongase-5, and stearoyl-coenzyme A (CoA) desaturase-2 levels and increased 3-hydroxy-3-methylglutaryl-CoA reductase mRNA expression in the liver compared with control rats. TAK-085 supplementation significantly increased stearoyl-CoA desaturase-2 mRNA expression. These results suggest that long-term supplementation with atorvastatin decreases the EPA and DHA levels by inhibiting the desaturation and elongation of n-3 fatty acid metabolism, while TAK-085 supplementation effectively replenishes this effect in SHRcp rat liver.

  10. The effect of conjugated linoleic acids (CLA) supplementation on the activity of enzymes participating in the formation of arachidonic acid in liver microsomes of rats--probable mechanism of CLA anticancer activity.

    PubMed

    Stawarska, Agnieszka; Białek, Agnieszka; Stanimirova, Ivana; Stawarski, Tomasz; Tokarz, Andrzej

    2015-01-01

    The aim of the present research was to examine the effect of conjugated linoleic acids (CLA) supplementation on the activity of enzymes that take part in the synthesis of arachidonic acid (AA) and also to investigate the relation between their activity and the neoplastic process. The enzyme activities were established indirectly, because their measure was the amount of AA formed in vitro, being developed from linoleic acid as determined in liver microsomes of Spraque-Dawley rats. In addition, the indices of Δ⁶-desaturase (D6D) and Δ⁵-desaturase (D5D) were determined. To this aim, the method of high per-formance liquid chromatography with UV/VIS detection was used. Between the examined groups, statistically significant differences were observed in the activities of enzymes as well as D6D. The carcinogenic agent applied (DMBA) was found to significantly increase the activity of the examined enzymes. Negative correlation was found between the activities of desaturases and CLA supplementation, whereas the activity of those enzymes was a little higher in the group of rats with chemically induced cancer process. The neoplastic process has a stimulating effect on the activity of D6D. The decrease of D6D activity, resulting from the presence of CLA in the animals' diet, may confirm the anticancer properties of these isomers.

  11. Hypoxia remodels the composition of the constituent ceramide species of HexCer and Hex2Cer with phytosphingosine and hydroxy fatty acids in human colon cancer LS174T cells.

    PubMed

    Tanaka, Kouji; Tamiya-Koizumi, Keiko; Yamada, Masaki; Murate, Takashi; Kannagi, Reiji; Kyogashima, Mamoru

    2015-11-01

    Oxygen-requiring enzymes, such as Δ4-desaturase (dihydroceramide desaturase), sphingolipid Δ4-desaturase/C-4-hydroxylase, and fatty acid 2-hydroxylase are involved in ceramide synthesis. We prepared free ceramides, sphingomyelins and glycosphingolipids (GSLs) from cancer cells cultivated under conditions of normoxia and hypoxia, and analyzed these compounds using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Human colon cancer LS174T cells were employed because these cells highly express hydroxyl fatty acids and phytosphingosine (t18:0) which are expected to be greatly influenced by changes in oxygen levels. As expected, the populations of dihydro-species of free ceramide and sphingomyelin with C16:0 non-hydroxy fatty acid were elevated, and the populations of HexCers and Hex2Cers, composed of C16:0 or C16:0 hydroxy fatty acid (C16:0h), and sphingosine (d18:1) or t18:0, were decreased under hypoxia. However, appreciable populations of HexCer and Hex2Cer species of C24:0 or C24:0h and t18:0 remained. These results suggest that the individual species of GSLs with fatty acids possessing different alkyl chain lengths, either non-hydroxy fatty acids or hydroxyl fatty acids, may be metabolized individually.

  12. Long-chain saturated and monounsaturated fatty acids associate with development of premature infants up to 18 months of age.

    PubMed

    Strandvik, Birgitta; Ntoumani, Eleni; Lundqvist-Persson, Cristina; Sabel, Karl-Göran

    2016-04-01

    Myelination is important perinatally and highly dependent on long-chain saturated and monounsaturated fatty acids. Long-chain polyunsaturated fatty acids, nowadays often supplemented, inhibit oleic acid synthesis. Using data from a premature cohort, we studied if nervonic, lignoceric and oleic acids correlated to growth and early development up to 18 months corrected age. Small for gestational age infants had lower concentrations than infants appropriate for gestational age. Only oleic acid was negatively correlated to long-chain polyunsaturated fatty acids. Oleic and lignoceric acids correlated to social interaction at one month, and nervonic acid to mental, psychomotor and behavioral development at 6, 10 and 18 months, also when adjusted for several confounders. Negative association between oleic acid and long-chain polyunsaturated fatty acids suggests inhibition of delta-9 desaturase, and nervonic acid´s divergent correlation to lignoceric and oleic acids suggests different metabolism in neonatal period. Our results may have implications for the supplementation of premature infants.

  13. Attenuation of UVR-induced vitamin D3 synthesis in a mouse model deleted for keratinocyte lathosterol 5-desaturase.

    PubMed

    Makarova, Anastasia M; Pasta, Saloni; Watson, Gordon; Shackleton, Cedric; Epstein, Ervin H

    2017-03-19

    The lower risk of some internal cancers at lower latitudes has been linked to greater sun exposure and consequent higher levels of ultraviolet radiation (UVR)-produced vitamin D3 (D3). To separate the experimental effects of sunlight and of all forms of D3, a mouse in which UVR does not produce D3 would be useful. To this end we have generated mice carrying a modified allele of sterol C5-desaturase (Sc5d), the gene encoding the enzyme that converts lathosterol to 7-dehydrocholesterol (7-DHC), such that Sc5d expression can be inactivated using the Cre/lox site-specific recombination system. By crossing to mice with tissue-specific expression of Cre or CreER(2) (Cre/estrogen receptor), we generated two lines of transgenic mice. One line has constitutive keratinocyte-specific inactivation of Sc5d (Sc5d(k14KO)). The other line (Sc5d(k14KOi)) has tamoxifen-inducible keratinocyte-specific inactivation of Sc5d. Mice deleted for keratinocyte Sc5d lose the ability to increase circulating D3 following UVR exposure of the skin. Thus, unlike in control mice, acute UVR exposure did not affect circulating D3 level in inducible Sc5d(k14KOi) mice. Keratinocyte-specific inactivation of Sc5d was proven by sterol measurement in hair - in control animals lathosterol and cholesta-7,24-dien-3β-ol, the target molecules of SC5D in the sterol biosynthetic pathways, together constituted a mean of 10% of total sterols; in the conditional knockout mice these sterols constituted a mean of 56% of total sterols. The constitutive knockout mice had an even greater increase, with lathosterol and cholesta-7,24-dien-3β-ol accounting for 80% of total sterols. In conclusion, the dominant presence of the 7-DHC precursors in hair of conditional animals and the lack of increased circulating D3 following exposure to UVR reflect attenuated production of the D3 photochemical precursor 7-DHC and, consequently, of D3 itself. These animals provide a useful new tool for investigating the role of D3 in UVR

  14. The fatty acid profile of subcutaneous and abdominal fat in dairy cows with left displacement of the abomasum.

    PubMed

    Hostens, M; Fievez, V; Leroy, J L M R; Van Ranst, J; Vlaeminck, B; Opsomer, G

    2012-07-01

    The objective of this study was to determine the fatty acid (FA) profile and assess desaturase indices of nonesterified fatty acids (NEFA) in the blood, as well as in the abdominal (ABD) and subcutaneous (SUBC) fat stores, in dairy cows with left displacement of the abomasum (LDA). Blood, ABD, and SUBC samples were taken from 50 Holstein cows offered for surgery to correct LDA. The FA profile of the 3 compartments was determined by gas chromatography after lipid extraction, methylation, and, in the case of blood plasma, separation of lipid classes. The most abundant FA in all 3 compartments were 16:0, 18:0, and 18:1 cis-9, with a total proportion of 82.5, 68.0, and 74.1g/100 g of FA in ABD, NEFA, and SUBC, respectively. A principal component analysis was performed on the entire FA profile as well as on the Δ(9)-desaturase indices (14:1 cis-9/14:0, 16:1 cis-9/16:0, 18:1 cis-9/18:0). The principal component analysis extracted 2 principal components (PC), representing 51.6% (PC1) and 21.1% (PC2) of the total variance in FA composition of the 3 compartments. The loading plot for the regression factors revealed a strong positive correlation between PC1 with the Δ(9)-desaturase indices and the proportions of 14:1 cis-9 and 16:1 cis-9, and revealed a negative correlation with the proportion of 18:0 and saturated FA. The correlation with PC2 was positive for the proportion of unsaturated FA, 18:2n-6, and 18:3n-3, and negative for the proportion of 14:0, 16:0, and saturated FA. The SUBC could be distinguished from the NEFA and ABD by a positive score for PC1, whereas differentiation among the latter 2 compartments could be made by a positive (NEFA) or negative (ABD) score for PC2. The Δ(9)-desaturase indices for C14 and C16 differed between all compartments but were numerically closer for NEFA and ABD versus NEFA and SUBC. The desaturase indices of the main FA (18:1 cis-9 and 18:0) did not differ between NEFA and ABD. These results support the existence of a different FA

  15. Expression of fatty-acid-modifying enzymes in the halotolerant black yeast Aureobasidium pullulans (de Bary) G. Arnaud under salt stress.

    PubMed

    Gostincar, C; Turk, M; Trbuha, T; Vaupotic, T; Plemenitas, A; Gunde-Cimerman, N

    2008-01-01

    Multiple tolerance to stressful environmental conditions of the black, yeast-like fungus Aureobasidium pullulans is achieved through different adaptations, among which there is the restructuring of the lipid composition of their membranes. Here, we describe three novel genes encoding fatty-acid-modifying enzymes in A. pullulans, along with the levels of their mRNAs under different salinity conditions. High levels of Delta(9)-desaturase and Delta(12)-desaturase mRNAs were seen at high salinities, which were consistent with an increased desaturation of the fatty acids in the cell membranes. Elevated levels of elongase mRNA were also detected. Surprisingly, increases in the levels of these mRNAs were also seen following hypo-osmotic shock, while hyperosmotic shock had exactly the opposite effect, demonstrating that data that are obtained from up-shift and down-shift salinity studies should be interpreted with caution.

  16. Expression of fatty-acid-modifying enzymes in the halotolerant black yeast Aureobasidium pullulans (de Bary) G. Arnaud under salt stress

    PubMed Central

    Gostinčar, C.; Turk, M.; Trbuha, T.; Vaupotič, T.; Plemenitaš, A.; Gunde-Cimerman, N.

    2008-01-01

    Multiple tolerance to stressful environmental conditions of the black, yeast-like fungus Aureobasidium pullulans is achieved through different adaptations, among which there is the restructuring of the lipid composition of their membranes. Here, we describe three novel genes encoding fatty-acid-modifying enzymes in A. pullulans, along with the levels of their mRNAs under different salinity conditions. High levels of Δ9-desaturase and Δ12-desaturase mRNAs were seen at high salinities, which were consistent with an increased desaturation of the fatty acids in the cell membranes. Elevated levels of elongase mRNA were also detected. Surprisingly, increases in the levels of these mRNAs were also seen following hypo-osmotic shock, while hyperosmotic shock had exactly the opposite effect, demonstrating that data that are obtained from up-shift and down-shift salinity studies should be interpreted with caution. PMID:19287526

  17. Kefir Grains Change Fatty Acid Profile of Milk during Fermentation and Storage

    PubMed Central

    Vieira, C. P.; Álvares, T. S.; Gomes, L. S.; Torres, A. G.; Paschoalin, V. M. F.; Conte-Junior, C. A.

    2015-01-01

    Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR), Viçosa (AV) e Lavras (AD)], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when p<0.05. The highest palmitic acid content, which is antimutagenic compost, was seen in AV grain (36.6g/100g fatty acids), which may have contributed to increasing the antimutagenic potential in fermented milk. Higher monounsaturated fatty acid (25.8g/100g fatty acids) and lower saturated fatty acid (72.7g/100g fatty acids) contents were observed in AV, when compared to other grains, due to higher Δ9-desaturase activity (0.31) that improves the nutritional quality of lipids. Higher oleic acid (25.0g/100g fatty acids) and monounsaturated fatty acid (28.2g/100g fatty acids) and lower saturated fatty acid (67.2g/100g fatty acids) contents were found in stored kefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality. PMID:26444286

  18. Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance.

    PubMed

    Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

    2015-11-01

    Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a "push" (synthesis) and "pull" (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses.

  19. Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum.

    PubMed

    Su, Gaomin; Jiao, Kailin; Li, Zheng; Guo, Xiaoyi; Chang, Jingyu; Ndikubwimana, Theoneste; Sun, Yong; Zeng, Xianhai; Lu, Yinghua; Lin, Lu

    2016-07-01

    Polyunsaturated fatty acids (PUFAs) are highly appreciated on their nutritive value for human health and aquaculture. P. purpureum, one of the red microalgae acknowledged as a promising accumulator of ARA, was chosen as the target algae in the present research. Effects of sodium bicarbonate (0.04-1.2 g/L), temperature (25, 30 and 33 °C) and phosphate (0.00-0.14 g/L) on biomass yield, total fatty acids (TFA) and arachidonic acid (ARA) accumulation were investigated systemically. NaHCO3 dose of 0.8 g/L and moderate temperature of 30 °C were preferred. In addition, TFA and ARA production were significantly enhanced by an appropriate concentration of phosphate, and the highest TFA yield of 666.38 mg/L and ARA yield of 159.74 mg/L were obtained at a phosphate concentration of 0.035 g/L. Interestingly, with phosphate concentration continuing to fall, UFA/TFA and ARA/EPA ratios were increased accordingly, suggesting that phosphate limitation promoted unsaturated fatty acids and arachidonic acid biosynthesis. Low concentration of phosphate may be favored to increase the enzymatic activities of ∆6-desaturase, which played a key role in catalyzing the conversion of C16:0 to C18:2, and thus the selectivity of UFA increased. Meanwhile, the increase of ARA selectivity could be attributed to ω6 pathway promotion and ∆17-desaturase activity inhibition with phosphate limitation. Phosphate limitation strategy enhanced unsaturated fatty acids and ARA biosynthesis in P. purpureum, and can be applied in commercial scale manufacturing and commercialization of ARA.

  20. EPA, DHA, and Lipoic Acid Differentially Modulate the n-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes.

    PubMed

    Bou, Marta; Østbye, Tone-Kari; Berge, Gerd M; Ruyter, Bente

    2017-03-01

    The aim of the present study was to investigate how EPA, DHA, and lipoic acid (LA) influence the different metabolic steps in the n-3 fatty acid (FA) biosynthetic pathway in hepatocytes from Atlantic salmon fed four dietary levels (0, 0.5, 1.0 and 2.0%) of EPA, DHA or a 1:1 mixture of these FA. The hepatocytes were incubated with [1-(14)C] 18:3n-3 in the presence or absence of LA (0.2 mM). Increased endogenous levels of EPA and/or DHA and LA exposure both led to similar responses in cells with reduced desaturation and elongation of [1-(14)C] 18:3n-3 to 18:4n-3, 20:4n-3, and EPA, in agreement with reduced expression of the Δ6 desaturase gene involved in the first step of conversion. DHA production, on the other hand, was maintained even in groups with high endogenous levels of DHA, possibly due to a more complex regulation of this last step in the n-3 metabolic pathway. Inhibition of the Δ6 desaturase pathway led to increased direct elongation to 20:3n-3 by both DHA and LA. Possibly the route by 20:3n-3 and then Δ8 desaturation to 20:4n-3, bypassing the first Δ6 desaturase step, can partly explain the maintained or even increased levels of DHA production. LA increased DHA production in the phospholipid fraction of hepatocytes isolated from fish fed 0 and 0.5% EPA and/or DHA, indicating that LA has the potential to further increase the production of this health-beneficial FA in fish fed diets with low levels of EPA and/or DHA.

  1. Cloning and phylogenetic analysis of a fatty acid elongase gene from Nannochloropsis oculata CS179

    NASA Astrophysics Data System (ADS)

    Pan, Kehou; Ma, Xiaolei; Yu, Jianzhong; Zhu, Baohua; Yang, Guanpin

    2009-12-01

    Nannochloropsis oculata CS179, a unicellular marine microalga, is rich in long-chain polyunsaturated fatty acids (LCPUFAs). Elongase and desaturase play a key role in the biosynthesis of PUFAs. A new elongase gene, which encodes 322 amino acids, was identified via RT-PCR and 5' and 3' RACE. The sequence of the elongase gene was blast-searched in the NCBI GenBank and showed a similarity to those of the cryptosporidium. But the NJ-tree revealed that the N. oculata CS179 elongase clustered with those of the microalgae Phaeodactylum tricornutum, Ostreococcus tauri and Thalassiosira pseudonana.

  2. Gamma-linolenic acid provides additional protection against ventricular fibrillation in aged rats fed linoleic acid rich diets.

    PubMed

    Charnock, J S

    2000-02-01

    Ligation of the coronary artery in rats produces severe ventricular fibrillation (VF) and malignant cardiac arrhythmia. Mortality increases with the age of the animal. Diets rich in saturated fatty acids (SF) but low in linoleic acid (LA) increase, but diets high in LA and low in SF decrease the severity of VF and mortality in older animals. The effects of an LA enriched diet can be blocked by inhibition of cyclooxygenase suggesting that conversion of LA to eicosanoids is central to the development of VF. Conversion of LA to gamma-linolenic acid (GLA) via delta-6 desaturase is the first step in the process. The activity of delta-6 desaturase declines with age. Thus inclusion of GLA in the diet of older animals may provide an additional benefit over LA alone. Dietary supplements of evening primrose oil (EPO) to one year old rats reduced ischaemic VF more than a supplement of sunflower seed oil (SSO) without GLA. Substitution of borage oil (more GLA than EPO but less LA than either EPO or SSO) was without additional benefit.

  3. Exploring the potential of the bacterial carotene desaturase CrtI to increase the beta-carotene content in Golden Rice.

    PubMed

    Al-Babili, Salim; Hoa, Tran Thi Cuc; Schaub, Patrick

    2006-01-01

    To increase the beta-carotene (provitamin A) content and thus the nutritional value of Golden Rice, the optimization of the enzymes employed, phytoene synthase (PSY) and the Erwinia uredovora carotene desaturase (CrtI), must be considered. CrtI was chosen for this study because this bacterial enzyme, unlike phytoene synthase, was expressed at barely detectable levels in the endosperm of the Golden Rice events investigated. The low protein amounts observed may be caused by either weak cauliflower mosaic virus 35S promoter activity in the endosperm or by inappropriate codon usage. The protein level of CrtI was increased to explore its potential for enhancing the flux of metabolites through the pathway. For this purpose, a synthetic CrtI gene with a codon usage matching that of rice storage proteins was generated. Rice plants were transformed to express the synthetic gene under the control of the endosperm-specific glutelin B1 promoter. In addition, transgenic plants expressing the original bacterial gene were generated, but the endosperm-specific glutelin B1 promoter was employed instead of the cauliflower mosaic virus 35S promoter. Independent of codon optimization, the use of the endosperm-specific promoter resulted in a large increase in bacterial desaturase production in the T(1) rice grains. However, this did not lead to a significant increase in the carotenoid content, suggesting that the bacterial enzyme is sufficiently active in rice endosperm even at very low levels and is not rate-limiting. The endosperm-specific expression of CrtI did not affect the carotenoid pattern in the leaves, which was observed upon its constitutive expression. Therefore, tissue-specific expression of CrtI represents the better option.

  4. Comparison of oleic acid metabolism in the soybean (Glycine max (L. ) Merr. ) genotypes Williams and A5, a mutant with decreased linoleic acid in the seed

    SciTech Connect

    Martin, B.A.; Rinne, R.W.

    1986-05-01

    The metabolism of oleoyl coenzyme A (CoA) was examined in developing seed from two soybean (Glycine max (L.) Merr.) genotypes: Williams, a standard cultivar and A5, a mutant containing nearly twice the oleic acid (18:1) content of Williams. The in vitro rates of esterification of oleoyl-CoA to lysophosphatides by acyl-CoA: lysophosphatidylcholine acyltransferase was similar in both genotypes and lysophosphatidyl-ethanolamine was a poor substrate. Crude extracts desaturated exogenous (1-/sup 14/C)dioleoyl phosphatidylcholine at 14% of the rate achieved with (1-/sup 14/C)oleoyl-CoA, and 50 micromolar lysophosphaatidylcholine. The desaturase enzyme also required NADH for full activity. Extracts from Williams contained 1.5-fold more oleoyl phosphatidylcholine desaturase activity, on a fresh weight basis, than did A5 and appeared to have a similar affinity for oleoyl-CoA. There was 1.2- to 1.9-fold more linoleic acid (18:2) in phosphatidylcholine from Williams than from A5, measured at two stages of development, but both genotypes had a similar distribution of fatty acids in the one and two positions. Phosphatidylethanolamine in A5 contained relatively more linoleic acid (18:2) in the one position than did Williams. The increased oleic acid (18:1) content in A5 appeared to be a result of decreased rates of 18:1 desaturation of oleoyl-phosphatidylcholine in this genotype.

  5. Chlorogenic acid from honeysuckle improves hepatic lipid dysregulation and modulates hepatic fatty acid composition in rats with chronic endotoxin infusion.

    PubMed

    Zhou, Yan; Ruan, Zheng; Wen, Yanmei; Yang, Yuhui; Mi, Shumei; Zhou, Lili; Wu, Xin; Ding, Sheng; Deng, Zeyuan; Wu, Guoyao; Yin, Yulong

    2016-03-01

    Chlorogenic acid as a natural hydroxycinnamic acid has protective effect for liver. Endotoxin induced metabolic disorder, such as lipid dysregulation and hyperlipidemia. In this study, we investigated the effect of chlorogenic acid in rats with chronic endotoxin infusion. The Sprague-Dawley rats with lipid metabolic disorder (LD group) were intraperitoneally injected endotoxin. And the rats of chlorogenic acid-LD group were daily received chlorogenic acid by intragastric administration. In chlorogenic acid-LD group, the area of visceral adipocyte was decreased and liver injury was ameliorated, as compared to LD group. In chlorogenic acid-LD group, serum triglycerides, free fatty acids, hepatic triglycerides and cholesterol were decreased, the proportion of C20:1, C24:1 and C18:3n-6, Δ9-18 and Δ6-desaturase activity index in the liver were decreased, and the proportion of C18:3n-3 acid was increased, compared to the LD group. Moreover, levels of phosphorylated AMP-activated protein kinase, carnitine palmitoyltransferase-I, and fatty acid β-oxidation were increased in chlorogenic acid-LD group compared to LD rats, whereas levels of fatty acid synthase and acetyl-CoA carboxylase were decreased. These findings demonstrate that chlorogenic acid effectively improves hepatic lipid dysregulation in rats by regulating fatty acid metabolism enzymes, stimulating AMP-activated protein kinase activation, and modulating levels of hepatic fatty acids.

  6. Modification of the liver fatty acids by Hibiscus sabdariffa Linnaeus (Malvaceae) infusion, its possible effect on vascular reactivity in a metabolic syndrome model.

    PubMed

    Pérez-Torres, Israel; Zúñiga Muñoz, Alejandra; Beltrán-Rodríguez, Ulises; Díaz-Díaz, Eulises; Martínez-Memije, Raúl; Guarner Lans, Verónica

    2014-01-01

    We investigated the effects of Hibiscus sabdariffa Linnaeus (HSL)-fed infusion on the fatty acid (FA) profile in liver of metabolic syndrome (MS) rats and its possible effect on vascular reactivity. Body mass, intra-abdominal fat, triglycerides, insulin, blood pressure, saturated, monounsaturated FA, NEFAs, Δ(9)-, Δ(6)-desaturases and vasoconstriction were increased, while vasorelaxation, polyunsaturated FA, endothelial nitric oxide and [Formula: see text]/[Formula: see text] ratio decreased in MS versus Control, but HSL infusion modified it and increased Δ(5)-desaturase. The results suggest that the alteration in FA liver metabolism in the MS contributes to impaired vascular reactivity, but treatment with of HSL infusion can improve this condition.

  7. Development of low-linolenic acid Brassica oleracea lines through seed mutagenesis and molecular characterization of mutants.

    PubMed

    Rahman, Habibur; Singer, Stacy D; Weselake, Randall J

    2013-06-01

    Designing the fatty acid composition of Brassica napus L. seed oil for specific applications would extend the value of this crop. A mutation in Fatty Acid Desaturase 3 (FAD3), which encodes the desaturase responsible for catalyzing the formation of α-linolenic acid (ALA; 18:3 (cisΔ9,12,15)), in a diploid Brassica species would potentially result in useful germplasm for creating an amphidiploid displaying low ALA content in the seed oil. For this, seeds of B. oleracea (CC), one of the progenitor species of B. napus, were treated with ethyl-methane-sulfonate to induce mutations in genes encoding enzymes involved in fatty acid biosynthesis. Seeds from 1,430 M2 plants were analyzed, from which M3 seed families with 5.7-6.9 % ALA were obtained. Progeny testing and selection for low ALA content were carried out in M3-M7 generations, from which mutant lines with <2.0 % ALA were obtained. Molecular analysis revealed that the mutation was due to a single nucleotide substitution from G to A in exon 3 of FAD3, which corresponds to an amino acid residue substitution from glutamic acid to lysine. No obvious differences in the expression of the FAD3 gene were detected between wild type and mutant lines; however, evaluation of the performance of recombinant Δ-15 desaturase from mutant lines in yeast indicated reduced production of ALA. The novelty of this mutation can be inferred from the position of the point mutation in the C-genome FAD3 gene when compared to the position of mutations reported previously by other researchers. This B. oleracea mutant line has the potential to be used for the development of low-ALA B. napus and B. carinata oilseed crops.

  8. Oleic acid attenuates trans-10,cis-12 conjugated linoleic acid-mediated inflammatory gene expression in human adipocytes.

    PubMed

    Reardon, Meaghan; Gobern, Semone; Martinez, Kristina; Shen, Wan; Reid, Tanya; McIntosh, Michael

    2012-11-01

    The weight loss supplement conjugated linoleic acid (CLA) consists of an equal mixture of trans-10,cis-12 (10,12) and cis-9,trans-11 (9,11) isomers. However, high levels of mixed CLA isomers, or the 10,12 isomer, causes chronic inflammation, lipodystrophy, or insulin resistance. We previously demonstrated that 10,12 CLA decreases de novo lipid synthesis along with the abundance and activity of stearoyl-CoA desaturase (SCD)-1, a δ-9 desaturase essential for the synthesis of monounsaturated fatty acids (MUFA). Thus, we hypothesized that the 10,12 CLA-mediated decrease in SCD-1, with the subsequent decrease in MUFA, was responsible for the observed effects. To test this hypothesis, 10,12 CLA-treated human adipocytes were supplemented with oleic acid for 12 h to 7 days, and inflammatory gene expression, insulin-stimulated glucose uptake, and lipid content were measured. Oleic acid reduced inflammatory gene expression in a dose-dependent manner, and restored the lipid content of 10,12 CLA-treated adipocytes without improving insulin-stimulated glucose uptake. In contrast, supplementation with stearic acid, a substrate for SCD-1, or 9,11 CLA did not prevent inflammatory gene expression by 10,12 CLA. Notably, 10,12 CLA impacted the expression of several G-protein coupled receptors that was attenuated by oleic acid. Collectively, these data show that oleic acid attenuates 10,12 CLA-induced inflammatory gene expression and lipid content, possibly by alleviating cell stress caused by the inhibition of MUFA needed for phospholipid and neutral lipid synthesis.

  9. Modulation of tissue fatty acids by L-carnitine attenuates metabolic syndrome in diet-induced obese rats.

    PubMed

    Panchal, Sunil K; Poudyal, Hemant; Ward, Leigh C; Waanders, Jennifer; Brown, Lindsay

    2015-08-01

    Obesity and dyslipidaemia are metabolic defects resulting from impaired lipid metabolism. These impairments are associated with the development of cardiovascular disease and non-alcoholic fatty liver disease. Correcting the defects in lipid metabolism may attenuate obesity and dyslipidaemia, and reduce cardiovascular risk and liver damage. L-Carnitine supplementation was used in this study to enhance fatty acid oxidation so as to ameliorate diet-induced disturbances in lipid metabolism. Male Wistar rats (8-9 weeks old) were fed with either corn starch or high-carbohydrate, high-fat diets for 16 weeks. Separate groups were supplemented with L-carnitine (1.2% in food) on either diet for the last 8 weeks of the protocol. High-carbohydrate, high-fat diet-fed rats showed central obesity, dyslipidaemia, hypertension, impaired glucose tolerance, hyperinsulinaemia, cardiovascular remodelling and non-alcoholic fatty liver disease. L-Carnitine supplementation attenuated these high-carbohydrate, high-fat diet-induced changes, together with modifications in lipid metabolism including the inhibition of stearoyl-CoA desaturase-1 activity, reduced storage of short-chain monounsaturated fatty acids in the tissues with decreased linoleic acid content and trans fatty acids stored in retroperitoneal fat. Thus, L-carnitine supplementation attenuated the signs of metabolic syndrome through inhibition of stearoyl-CoA desaturase-1 activity, preferential β-oxidation of some fatty acids and increased storage of saturated fatty acids and relatively inert oleic acid in the tissues.

  10. Dietary fatty acids modulate associations between genetic variants and circulating fatty acids in plasma and erythrocyte membranes: meta-analysis of 9 studies in the CHARGE consortium

    PubMed Central

    Smith, Caren E.; Follis, Jack L.; Nettleton, Jennifer A.; Foy, Millennia; Wu, Jason H.Y.; Ma, Yiyi; Tanaka, Toshiko; Manichakul, Ani W.; Wu, Hongyu; Chu, Audrey Y.; Steffen, Lyn M.; Fornage, Myriam; Mozaffarian, Dariush; Kabagambe, Edmond K.; Ferruci, Luigi; da Chen, Yii-Der I; Rich, Stephen S.; Djoussé, Luc; Ridker, Paul M.; Tang, Weihong; McKnight, Barbara; Tsai, Michael Y.; Bandinelli, Stefania; Rotter, Jerome I.; Hu, Frank B.; Chasman, Daniel I.; Psaty, Bruce M.; Arnett, Donna K.; King, Irena B.; Sun, Qi; Wang, Lu; Lumley, Thomas; Chiuve, Stephanie E.; Siscovick, David S; Ordovás, José M.; Lemaitre, Rozenn N.

    2015-01-01

    Scope Tissue concentrations of omega-3 fatty acids may reduce cardiovascular disease risk, and genetic variants are associated with circulating fatty acids concentrations. Whether dietary fatty acids interact with genetic variants to modify circulating omega-3 fatty acids is unclear. Objective We evaluated interactions between genetic variants and fatty acid intakes for circulating alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). Methods and Results We conducted meta-analyses (N to 11,668) evaluating interactions between dietary fatty acids and genetic variants (rs174538 and rs174548 in FADS1 (fatty acid desaturase 1), rs7435 in AGPAT3 (1-acyl-sn-glycerol-3-phosphate), rs4985167 in PDXDC1 (pyridoxal-dependent decarboxylase domain-containing 1), rs780094 in GCKR (glucokinase regulatory protein) and rs3734398 in ELOVL2 (fatty acid elongase 2)). Stratification by measurement compartment (plasma vs. erthyrocyte) revealed compartment-specific interactions between FADS1 rs174538 and rs174548 and dietary ALA and linoleic acid for DHA and DPA. Conclusion Our findings reinforce earlier reports that genetically-based differences in circulating fatty acids may be partially due to differences in the conversion of fatty acid precursors. Further, fatty acids measurement compartment may modify gene-diet relationships, and considering compartment may improve the detection of gene-fatty acids interactions for circulating fatty acid outcomes. PMID:25626431

  11. Solid-state NMR studies of a diverged microsomal amino-proximate delta12 desaturase peptide reveal causes of stability in bilayer: tyrosine anchoring and arginine snorkeling.

    PubMed

    Gibbons, William J; Karp, Ethan S; Cellar, Nick A; Minto, Robert E; Lorigan, Gary A

    2006-02-15

    This study reports the solid-state NMR spectroscopic characterization of the amino-proximate transmembrane domain (TM-A) of a diverged microsomal delta12-desaturase (CREP-1) in a phospholipid bilayer. A series of TM-A peptides were synthesized with 2H-labeled side chains (Ala-53, -56, and -63, Leu-62, Val-50), and their dynamic properties were studied in 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) bilayers at various temperatures. At 6 mol % peptide to lipid, 31P NMR spectra indicated that the peptides did not significantly disrupt the phospholipid bilayer in the L(alpha) phase. The 2H NMR spectra from Ala-53 and Ala-56 samples revealed broad Pake patterns with quadrupolar splittings of 16.9 kHz and 13.3 kHz, respectively, indicating restricted motion confined within the hydrocarbon core of the phospholipid bilayer. Conversely, the deuterated Ala-63 sample revealed a peak centered at 0 kHz with a linewidth of 1.9 kHz, indicating increased side-chain motion and solvent exposure relative to the spectra of the other Ala residues. Val-50 and Leu-62 showed Pake patterns, with quadrupolar splittings of 3.5 kHz and 3.7 kHz, respectively, intermediate to Ala-53/Ala-56 and Ala-63. This indicates partial motional averaging and supports a model with the Val and Leu residues embedded inside the lipid bilayer. Solid-state NMR spectroscopy performed on the 2H-labeled Ala-56 TM-A peptide incorporated into magnetically aligned phospholipid bilayers indicated that the peptide is tilted 8 degrees with respect to the membrane normal of the lipid bilayer. Snorkeling and anchoring interactions of Arg-44 and Tyr-60, respectively, with the polar region or polar hydrophobic interface of the lipid bilayer are suggested as control elements for insertional depth and orientation of the helix in the lipid matrix. Thus, this study defines the location of key residues in TM-A with respect to the lipid bilayer, describes the conformation of TM-A in a biomembrane mimic, presents a

  12. Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance[S

    PubMed Central

    Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

    2015-01-01

    Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a “push” (synthesis) and “pull” (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses. PMID:26323290

  13. The heparan and heparin metabolism pathway is involved in regulation of fatty acid composition.

    PubMed

    Jiang, Zhihua; Michal, Jennifer J; Wu, Xiao-Lin; Pan, Zengxiang; MacNeil, Michael D

    2011-01-01

    Six genes involved in the heparan sulfate and heparin metabolism pathway, DSEL (dermatan sulfate epimerase-like), EXTL1 (exostoses (multiple)-like 1), HS6ST1 (heparan sulfate 6-O-sulfotransferase 1), HS6ST3 (heparan sulfate 6-O-sulfotransferase 3), NDST3 (N-deacetylase/N-sulfotransferase (heparan glucosaminyl) 3), and SULT1A1 (sulfotransferase family, cytosolic, 1A, phenol-preferring, member 1), were investigated for their associations with muscle lipid composition using cattle as a model organism. Nineteen single nucleotide polymorphisms (SNPs)/multiple nucleotide length polymorphisms (MNLPs) were identified in five of these six genes. Six of these mutations were then genotyped on 246 Wagyu x Limousin F(2) animals, which were measured for 5 carcass, 6 eating quality and 8 fatty acid composition traits. Association analysis revealed that DSEL, EXTL1 and HS6ST1 significantly affected two stearoyl-CoA desaturase activity indices, the amount of conjugated linoleic acid (CLA), and the relative amount of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in skeletal muscle (P<0.05). In particular, HS6ST1 joined our previously reported SCD1 and UQCRC1 genes to form a three gene network for one of the stearoyl-CoA desaturase activity indices. These results provide evidence that genes involved in heparan sulfate and heparin metabolism are also involved in regulation of lipid metabolism in bovine muscle. Whether the SNPs affected heparan sulfate proteoglycan structure is unknown and warrants further investigation.

  14. Reduction of body weight, liver steatosis and expression of stearoyl-CoA desaturase 1 by the isoflavone daidzein in diet-induced obesity

    PubMed Central

    Crespillo, A; Alonso, M; Vida, M; Pavón, FJ; Serrano, A; Rivera, P; Romero-Zerbo, Y; Fernández-Llebrez, P; Martínez, A; Pérez-Valero, V; Bermúdez-Silva, FJ; Suárez, J; de Fonseca, FR

    2011-01-01

    BACKGROUND AND PURPOSE The lack of safe and effective treatments for obesity has increased interest in natural products that may serve as alternative therapies. From this perspective, we have analysed the effects of daidzein, one of the main soy isoflavones, on diet-induced obesity in rats. EXPERIMENTAL APPROACH Rats made obese after exposure to a very (60%) high fat-content diet were treated with daidzein (50 mg·kg−1) for 14 days. The dose was selected on the basis of the acute effects of this isoflavone on a feeding test. After 14 days, animals were killed and plasma, white and brown adipose tissue, muscle and liver studied for the levels and expression of metabolites, proteins and genes relevant to lipid metabolism. KEY RESULTS A single treatment (acute) with daidzein dose-dependently reduced food intake. Chronic treatment (daily for 14 days) reduced weight gain and fat content in liver, accompanied by high leptin and low adiponectin levels in plasma. While skeletal muscle was weakly affected by treatment, both adipose tissue and liver displayed marked changes after treatment with daidzein, affecting transcription factors and lipogenic enzymes, particularly stearoyl coenzyme A desaturase 1, a pivotal enzyme in obesity. Expression of uncoupling protein 1, an important enzyme for thermogenesis, was increased in brown adipose tissue after daidzein treatment. CONCLUSIONS AND IMPLICATIONS These results support the use of isoflavones in diet-induced obesity, especially when hepatic steatosis is present and open a new field of use for these natural products. PMID:21557739

  15. Effect of Exercise and Calorie Restriction on Tissue Acylcarnitines, Tissue Desaturase Indices, and Fat Accumulation in Diet-Induced Obese Rats.

    PubMed

    Gopalan, Venkatesh; Michael, Navin; Ishino, Seigo; Lee, Swee Shean; Yang, Adonsia Yating; Bhanu Prakash, K N; Yaligar, Jadegoud; Sadananthan, Suresh Anand; Kaneko, Manami; Zhou, Zhihong; Satomi, Yoshinori; Hirayama, Megumi; Kamiguchi, Hidenori; Zhu, Bin; Horiguchi, Takashi; Nishimoto, Tomoyuki; Velan, S Sendhil

    2016-05-20

    Both exercise and calorie restriction interventions have been recommended for inducing weight-loss in obese states. However, there is conflicting evidence on their relative benefits for metabolic health and insulin sensitivity. This study seeks to evaluate the differential effects of the two interventions on fat mobilization, fat metabolism, and insulin sensitivity in diet-induced obese animal models. After 4 months of ad libitum high fat diet feeding, 35 male Fischer F344 rats were grouped (n = 7 per cohort) into sedentary control (CON), exercise once a day (EX1), exercise twice a day (EX2), 15% calorie restriction (CR1) and 30% calorie restriction (CR2) cohorts. Interventions were carried out over a 4-week period. We found elevated hepatic and muscle long chain acylcarnitines with both exercise and calorie restriction, and a positive association between hepatic long chain acylcarnitines and insulin sensitivity in the pooled cohort. Our result suggests that long chain acylcarnitines may not indicate incomplete fat oxidation in weight loss interventions. Calorie restriction was found to be more effective than exercise in reducing body weight. Exercise, on the other hand, was more effective in reducing adipose depots and muscle triglycerides, favorably altering muscle/liver desaturase activity and improving insulin sensitivity.

  16. Expression of a desaturase gene, desat1, in neural and nonneural tissues separately affects perception and emission of sex pheromones in Drosophila

    PubMed Central

    Bousquet, François; Nojima, Tetsuya; Houot, Benjamin; Chauvel, Isabelle; Chaudy, Sylvie; Dupas, Stéphane; Yamamoto, Daisuke; Ferveur, Jean-François

    2012-01-01

    Animals often use sex pheromones for mate choice and reproduction. As for other signals, the genetic control of the emission and perception of sex pheromones must be tightly coadapted, and yet we still have no worked-out example of how these two aspects interact. Most models suggest that emission and perception rely on separate genetic control. We have identified a Drosophila melanogaster gene, desat1, that is involved in both the emission and the perception of sex pheromones. To explore the mechanism whereby these two aspects of communication interact, we investigated the relationship between the molecular structure, tissue-specific expression, and pheromonal phenotypes of desat1. We characterized the five desat1 transcripts—all of which yielded the same desaturase protein—and constructed transgenes with the different desat1 putative regulatory regions. Each region was used to target reporter transgenes with either (i) the fluorescent GFP marker to reveal desat1 tissue expression, or (ii) the desat1 RNAi sequence to determine the effects of genetic down-regulation on pheromonal phenotypes. We found that desat1 is expressed in a variety of neural and nonneural tissues, most of which are involved in reproductive functions. Our results suggest that distinct desat1 putative regulatory regions independently drive the expression in nonneural and in neural cells, such that the emission and perception of sex pheromones are precisely coordinated in this species. PMID:22114190

  17. Effect of Exercise and Calorie Restriction on Tissue Acylcarnitines, Tissue Desaturase Indices, and Fat Accumulation in Diet-Induced Obese Rats

    PubMed Central

    Gopalan, Venkatesh; Michael, Navin; Ishino, Seigo; Lee, Swee Shean; Yang, Adonsia Yating; Bhanu Prakash, K. N.; Yaligar, Jadegoud; Sadananthan, Suresh Anand; Kaneko, Manami; Zhou, Zhihong; Satomi, Yoshinori; Hirayama, Megumi; Kamiguchi, Hidenori; Zhu, Bin; Horiguchi, Takashi; Nishimoto, Tomoyuki; Velan, S. Sendhil

    2016-01-01

    Both exercise and calorie restriction interventions have been recommended for inducing weight-loss in obese states. However, there is conflicting evidence on their relative benefits for metabolic health and insulin sensitivity. This study seeks to evaluate the differential effects of the two interventions on fat mobilization, fat metabolism, and insulin sensitivity in diet-induced obese animal models. After 4 months of ad libitum high fat diet feeding, 35 male Fischer F344 rats were grouped (n = 7 per cohort) into sedentary control (CON), exercise once a day (EX1), exercise twice a day (EX2), 15% calorie restriction (CR1) and 30% calorie restriction (CR2) cohorts. Interventions were carried out over a 4-week period. We found elevated hepatic and muscle long chain acylcarnitines with both exercise and calorie restriction, and a positive association between hepatic long chain acylcarnitines and insulin sensitivity in the pooled cohort. Our result suggests that long chain acylcarnitines may not indicate incomplete fat oxidation in weight loss interventions. Calorie restriction was found to be more effective than exercise in reducing body weight. Exercise, on the other hand, was more effective in reducing adipose depots and muscle triglycerides, favorably altering muscle/liver desaturase activity and improving insulin sensitivity. PMID:27197769

  18. Biosynthesis of gamma-linolenic acid in cotyledons and microsomal preparations of the developing seeds of common borage (Borago officinalis).

    PubMed Central

    Stymne, S; Stobart, A K

    1986-01-01

    The developing seeds of Borago officinalis (common borage) accumulate a triacylglycerol oil that is relatively rich in the uncommon fatty acid gamma-linolenate (octadec-6,9,12-trienoic acid). Incubation of developing, whole, cotyledons with [14C]oleate and [14C]linoleate showed that the gamma-linolenate was synthesized by the sequential desaturation of oleate----linoleate----gamma-linolenate. Microsomal membrane preparations from the developing cotyledons contained an active delta 6-desaturase enzyme that catalysed the conversion of linoleate into gamma-linolenate. Experiments were designed to manipulate the [14C]linoleate content of the microsomal phosphatidylcholine. The [14C]linoleoyl phosphatidylcholine labelled in situ was converted into gamma-linolenoyl phosphatidylcholine in the presence of NADH. The substrate for the delta 6-desaturase in borage was, therefore, the linoleate in the complex microsomal lipid phosphatidylcholine, rather than, as in animals, the acyl-CoA. This was further confirmed in experiments that compared the specific radioactivity of the gamma-linolenate, in acyl-CoA and phosphatidylcholine, that was synthesized when [14C]linoleoyl-CoA was incubated with microsomal membranes, NADH and non-radioactive gamma-linolenoyl-CoA. The delta 6-desaturase was positionally specific and only utilized the linoleate in position 2 of sn-phosphatidylcholine. Analysis of the positional distribution of fatty acids in the endogenous microsomal sn-phosphatidylcholine showed that, whereas position 1 contained substantial linoleate, only small amounts of gamma-linolenate were present. The results shed further light on the synthesis of C18 polyunsaturated fatty acids in plants and in particular its relationship to the regulation of the acyl quality of the triacylglycerols in oilseeds. PMID:3028375

  19. Biosynthesis of gamma-linolenic acid in cotyledons and microsomal preparations of the developing seeds of common borage (Borago officinalis).

    PubMed

    Stymne, S; Stobart, A K

    1986-12-01

    The developing seeds of Borago officinalis (common borage) accumulate a triacylglycerol oil that is relatively rich in the uncommon fatty acid gamma-linolenate (octadec-6,9,12-trienoic acid). Incubation of developing, whole, cotyledons with [14C]oleate and [14C]linoleate showed that the gamma-linolenate was synthesized by the sequential desaturation of oleate----linoleate----gamma-linolenate. Microsomal membrane preparations from the developing cotyledons contained an active delta 6-desaturase enzyme that catalysed the conversion of linoleate into gamma-linolenate. Experiments were designed to manipulate the [14C]linoleate content of the microsomal phosphatidylcholine. The [14C]linoleoyl phosphatidylcholine labelled in situ was converted into gamma-linolenoyl phosphatidylcholine in the presence of NADH. The substrate for the delta 6-desaturase in borage was, therefore, the linoleate in the complex microsomal lipid phosphatidylcholine, rather than, as in animals, the acyl-CoA. This was further confirmed in experiments that compared the specific radioactivity of the gamma-linolenate, in acyl-CoA and phosphatidylcholine, that was synthesized when [14C]linoleoyl-CoA was incubated with microsomal membranes, NADH and non-radioactive gamma-linolenoyl-CoA. The delta 6-desaturase was positionally specific and only utilized the linoleate in position 2 of sn-phosphatidylcholine. Analysis of the positional distribution of fatty acids in the endogenous microsomal sn-phosphatidylcholine showed that, whereas position 1 contained substantial linoleate, only small amounts of gamma-linolenate were present. The results shed further light on the synthesis of C18 polyunsaturated fatty acids in plants and in particular its relationship to the regulation of the acyl quality of the triacylglycerols in oilseeds.

  20. A Mediator subunit, MDT-15, integrates regulation of fatty acid metabolism by NHR-49-dependent and -independent pathways in C. elegans

    PubMed Central

    Taubert, Stefan; Van Gilst, Marc R.; Hansen, Malene; Yamamoto, Keith R.

    2006-01-01

    The Caenorhabditis elegans Nuclear Hormone Receptor NHR-49 coordinates expression of fatty acid (FA) metabolic genes during periods of feeding and in response to fasting. Here we report the identification of MDT-15, a subunit of the C. elegans Mediator complex, as an NHR-49-interacting protein and transcriptional coactivator. Knockdown of mdt-15 by RNA interference (RNAi) prevented fasting-induced mRNA accumulation of NHR-49 targets in vivo, and fasting-independent expression of other NHR-49 target genes, including two FA-Δ9-desaturases (fat-5, fat-7). Interestingly, mdt-15 RNAi affected additional FA-metabolism genes (including the third FA-Δ9-desaturase, fat-6) that are regulated independently of NHR-49, suggesting that distinct unidentified regulatory factors also recruit MDT-15 to selectively modulate metabolic gene expression. The deregulation of FA-Δ9-desaturases by knockdown of mdt-15 correlated with dramatically decreased levels of unsaturated FAs and multiple deleterious phenotypes (short life span, sterility, uncoordinated locomotion, and morphological defects). Importantly, dietary addition of specific polyunsaturated FAs partially suppressed these pleiotropic phenotypes. Thus, failure to properly govern FA-Δ9-desaturation contributed to decreased nematode viability. Our findings imply that a single subunit of the Mediator complex, MDT-15, integrates the activities of several distinct regulatory factors to coordinate metabolic and hormonal regulation of FA metabolism. PMID:16651656

  1. A Mediator subunit, MDT-15, integrates regulation of fatty acid metabolism by NHR-49-dependent and -independent pathways in C. elegans.

    PubMed

    Taubert, Stefan; Van Gilst, Marc R; Hansen, Malene; Yamamoto, Keith R

    2006-05-01

    The Caenorhabditis elegans Nuclear Hormone Receptor NHR-49 coordinates expression of fatty acid (FA) metabolic genes during periods of feeding and in response to fasting. Here we report the identification of MDT-15, a subunit of the C. elegans Mediator complex, as an NHR-49-interacting protein and transcriptional coactivator. Knockdown of mdt-15 by RNA interference (RNAi) prevented fasting-induced mRNA accumulation of NHR-49 targets in vivo, and fasting-independent expression of other NHR-49 target genes, including two FA-Delta9-desaturases (fat-5, fat-7). Interestingly, mdt-15 RNAi affected additional FA-metabolism genes (including the third FA-Delta9-desaturase, fat-6) that are regulated independently of NHR-49, suggesting that distinct unidentified regulatory factors also recruit MDT-15 to selectively modulate metabolic gene expression. The deregulation of FA-Delta9-desaturases by knockdown of mdt-15 correlated with dramatically decreased levels of unsaturated FAs and multiple deleterious phenotypes (short life span, sterility, uncoordinated locomotion, and morphological defects). Importantly, dietary addition of specific polyunsaturated FAs partially suppressed these pleiotropic phenotypes. Thus, failure to properly govern FA-Delta9-desaturation contributed to decreased nematode viability. Our findings imply that a single subunit of the Mediator complex, MDT-15, integrates the activities of several distinct regulatory factors to coordinate metabolic and hormonal regulation of FA metabolism.

  2. Temperature-sensitive, Post-translational Regulation of Plant Omega-3 Fatty-acid Desaturases is Mediated by the Endoplasmic Reticulum-associated Degradation Pathway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in ambient temperature represent a major physiological challenge to poikilothermic organisms that requires rapid adjustments in the composition of cellular membranes in order to preserve overall membrane dynamics and integrity. In plants, the endoplasmic reticulum-localized omega-3 fatty ac...

  3. The toc132toc120 heterozygote mutant of Arabidopsis thaliana accumulates reduced levels of hexadecatrienoic acid.

    PubMed

    Afitlhile, Meshack; Duffield-Duncan, Kayla; Fry, Morgan; Workman, Samantha; Hum-Musser, Sue; Hildebrand, David

    2015-11-01

    A null and heterozygous mutant for the Arabidopsis thaliana TOC132 and TOC120 genes accumulates increased levels of 16:0 and decreased 16:3, suggesting altered homeostasis in fatty acid synthesis. The FAD5 gene encodes a plastid desaturase that catalyzes the first step in the synthesis of 16:3 in monogalactosyldiacylglycerol (MGDG). In non-acclimated toc132toc120+/- mutant plants, the FAD5 gene was repressed and this correlated with decreased levels of 16:3. In cold-acclimated mutant however, the FAD5 gene was upregulated and there was a small increase in 16:3 levels relative to the non-acclimated mutant plants. The MGD1 gene was expressed at control levels and the mutant accumulated levels of MGDG that were similar to the wild type. In the mutant however, MGDG had decreased 16:3 levels, suggesting that the activity of FAD5 desaturase was compromised. In the mutant, the FAD2 and FAD3 genes were downregulated but levels of 18:3-PC were increased, suggesting posttranscriptional regulation for the ER-localized fatty acid desaturases. The Toc120 or Toc159 receptor is likely to compensate for a defective Toc132 receptor. In the cold-acclimated mutant, the TOC159 gene was repressed ca. 300-fold, whereas the TOC120 gene was repressed 7-fold relative to the non-acclimated wild type. Thus, the TOC159 gene is more sensitive to cold-stress and might not compensate for defect in the TOC132 gene under these conditions. Overall, these data show that a mutation in the TOC132 gene results in decreased 16:3 levels, indicating the need for an intact Toc132/Toc120 receptor, presumably to facilitate the import of the FAD5 preprotein into chloroplasts.

  4. Alteration of seed fatty acid composition by an ethyl methanesulfonate-induced mutation in Arabidopsis thaliana affecting diacylglycerol acyltransferase activity.

    PubMed Central

    Katavic, V; Reed, D W; Taylor, D C; Giblin, E M; Barton, D L; Zou, J; Mackenzie, S L; Covello, P S; Kunst, L

    1995-01-01

    In characterizing the enzymes involved in the formation of very long-chain fatty acids (VLCFAs) in the Brassicaceae, we have generated a series of mutants of Arabidopsis thaliana that have reduced VLCFA content. Here we report the characterization of a seed lipid mutant, AS11, which, in comparison to wild type (WT), has reduced levels of 20:1 and 18:1 and accumulates 18:3 as the major fatty acid in triacylglycerols. Proportions of 18:2 remain similar to WT. Genetic analyses indicate that the fatty acid phenotype is caused by a semidominant mutation in a single nuclear gene, designated TAG1, located on chromosome 2. Biochemical analyses have shown that the AS11 phenotype is not due to a deficiency in the capacity to elongate 18:1 or to an increase in the relative delta 15 or delta 12 desaturase activities. Indeed, the ratio of desaturase/elongase activities measured in vitro is virtually identical in developing WT and AS11 seed homogenates. Rather, the fatty acid phenotype of AS11 is the result of reduced diacylglycerol acyltransferase activity throughout development, such that triacylglycerol biosynthesis is reduced. This leads to a reduction in 20:1 biosynthesis during seed development, leaving more 18:1 available for desaturation. Thus, we have demonstrated that changes to triacylglycerol biosynthesis can result in dramatic changes in fatty acid composition and, in particular, in the accumulation of VLCFAs in seed storage lipids. PMID:7784510

  5. A High-Fat, High-Oleic Diet, But Not a High-Fat, Saturated Diet, Reduces Hepatic α-Linolenic Acid and Eicosapentaenoic Acid Content in Mice.

    PubMed

    Picklo, Matthew J; Murphy, Eric J

    2016-05-01

    Considerable research has focused upon the role of linoleic acid (LNA; 18:2n-6) as a competitive inhibitor of α-linolenic (ALA; 18:3n-3) metabolism; however, little data exist as to the impact of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) on ALA metabolism. We tested the hypothesis that a high SFA diet, compared to a high MUFA (oleic acid 18:1n-9) diet, reduces ALA conversion to long chain n-3 fatty acids. Mice were fed for 12 weeks on three diets: (1) a control, 16 % fat energy diet consisting of similar levels of SFA and MUFA (2) a 50 % fat energy high MUFA energy diet (35 % MUFA and 7 % SFA) or (3) a 50 % fat energy, high SFA energy diet (34 % SFA, 8 % MUFA). ALA and LNA content remained constant. Analysis of hepatic lipids demonstrated a selective reduction (40 %) in ALA but not LNA and a 35 % reduction in eicosapentaenoic acid (EPA; 20:5n-3) in the high MUFA mice compared to the other groups. Lower content of ALA was reflected in the neutral lipid fraction, while smaller levels of phospholipid esterified EPA and docosapentaenoic acid (DPA; 22:5n-3) were evident. Docosahexaenoic acid (DHA; 22:6n-3) content was elevated by the high SFA diet. Expression of Fads1 (Δ5 desaturase) and Fads2 (Δ6 desaturase) was elevated by the high MUFA and reduced by the high SFA diet. These data indicate that a high MUFA diet, but not a high SFA diet, reduces ALA metabolism and point to selective hepatic disposition of ALA versus LNA.

  6. Temperature Increase Negatively Affects the Fatty Acid Bioconversion Capacity of Rainbow Trout (Oncorhynchus mykiss) Fed a Linseed Oil-Based Diet

    PubMed Central

    Mellery, Julie; Geay, Florian; Tocher, Douglas R.; Kestemont, Patrick; Debier, Cathy; Rollin, Xavier; Larondelle, Yvan

    2016-01-01

    Aquaculture is meant to provide fish rich in omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA). This objective must be reached despite (1) the necessity to replace the finite and limited fish oil in feed production and (2) the increased temperature of the supply water induced by the global warming. The objective of the present paper was to determine to what extent increased water temperature influences the fatty acid bioconversion capacity of rainbow trout (Oncorhynchus mykiss) fed a plant-derived diet. Fish were fed two diets formulated with fish oil (FO) or linseed oil (LO) as only added lipid source at the optimal water temperature of 15°C or at the increased water temperature of 19°C for 60 days. We observed that a temperature increase close to the upper limit of the species temperature tolerance range negatively affected the feed efficiency of rainbow trout fed LO despite a higher feed intake. The negative impact of increased water temperature on fatty acid bioconversion capacity appeared also to be quite clear considering the reduced expression of fatty acid desaturase 2 in liver and intestine and the reduced Δ6 desaturase enzymatic activity in intestinal microsomes. The present results also highlighted a negative impact of increased temperature on the apparent in vivo enzymatic activity of Δ5 and Δ6 desaturases of fish fed LO. Interestingly, this last parameter appeared less affected than those mentioned above. This study highlights that the increased temperature that rainbow trout may face due to global warming could reduce their fatty acid bioconversion capacity. The unavoidable replacement of finite fish oil by more sustainable, readily available and economically viable alternative lipid sources in aquaculture feeds should take this undeniable environmental issue on aquaculture productivity into account. PMID:27736913

  7. Vegetable oils rich in alpha linolenic acid increment hepatic n-3 LCPUFA, modulating the fatty acid metabolism and antioxidant response in rats.

    PubMed

    Rincón-Cervera, Miguel Ángel; Valenzuela, Rodrigo; Hernandez-Rodas, María Catalina; Barrera, Cynthia; Espinosa, Alejandra; Marambio, Macarena; Valenzuela, Alfonso

    2016-08-01

    Alpha-linolenic acid (C18:3 n-3, ALA) is an essential fatty acid and the metabolic precursor of long-chain polyunsaturated fatty acids (LCPUFA) from the n-3 family with relevant physiological and metabolic roles: eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n-3, DHA). Western diet lacks of suitable intake of n-3 LCPUFA and there are recommendations to increase the dietary supply of such nutrients. Seed oils rich in ALA such as those from rosa mosqueta (Rosa rubiginosa), sacha inchi (Plukenetia volubis) and chia (Salvia hispanica) may constitute an alternative that merits research. This study evaluated hepatic and epididymal accretion and biosynthesis of n-3 LCPUFA, the activity and expression of Δ-5 and Δ-6 desaturase enzymes, the expression and DNA-binding activity of PPAR-α and SREBP-1c, oxidative stress parameters and the activity of antioxidative enzymes in rats fed sunflower oil (SFO, 1% ALA) as control group, canola oil (CO, 10% ALA), rosa mosqueta oil (RMO, 33% ALA), sacha inchi oil (SIO, 49% ALA) and chia oil (ChO, 64% ALA) as single lipid source. A larger supply of ALA increased the accretion of n-3 LCPUFA, the activity and expression of desaturases, the antioxidative status, the expression and DNA-binding of PPAR-α, the oxidation of fatty acids and the activity of antioxidant enzymes, whereas the expression and DNA-binding activity of SREBP-1c transcription factor and the biosynthetic activity of fatty acids declined. Results showed that oils rich in ALA such as SIO and ChO may trigger metabolic responses in rats such as those produced by n-3 PUFA.

  8. Macrophage migration inhibitory factor and stearoyl-CoA desaturase 1: potential prognostic markers for soft tissue sarcomas based on bioinformatics analyses.

    PubMed

    Takahashi, Hiro; Nakayama, Robert; Hayashi, Shuhei; Nemoto, Takeshi; Murase, Yasuyuki; Nomura, Koji; Takahashi, Teruyoshi; Kubo, Kenji; Marui, Shigetaka; Yasuhara, Koji; Nakamura, Tetsuro; Sueo, Takuya; Takahashi, Anna; Tsutsumiuchi, Kaname; Ohta, Tsutomu; Kawai, Akira; Sugita, Shintaro; Yamamoto, Shinjiro; Kobayashi, Takeshi; Honda, Hiroyuki; Yoshida, Teruhiko; Hasegawa, Tadashi

    2013-01-01

    The diagnosis and treatment of soft tissue sarcomas (STSs) has been particularly difficult, because STSs are a group of highly heterogeneous tumors in terms of histopathology, histological grade, and primary site. Recent advances in genome technologies have provided an excellent opportunity to determine the complete biological characteristics of neoplastic tissues, resulting in improved diagnosis, treatment selection, and investigation of therapeutic targets. We had previously developed a novel bioinformatics method for marker gene selection and applied this method to gene expression data from STS patients. This previous analysis revealed that the extracted gene combination of macrophage migration inhibitory factor (MIF) and stearoyl-CoA desaturase 1 (SCD1) is an effective diagnostic marker to discriminate between subtypes of STSs with highly different outcomes. In the present study, we hypothesize that the combination of MIF and SCD1 is also a prognostic marker for the overall outcome of STSs. To prove this hypothesis, we first analyzed microarray data from 88 STS patients and their outcomes. Our results show that the survival rates for MIF- and SCD1-positive groups were lower than those for negative groups, and the p values of the log-rank test are 0.0146 and 0.00606, respectively. In addition, survival rates are more significantly different (p = 0.000116) between groups that are double-positive and double-negative for MIF and SCD1. Furthermore, in vitro cell growth inhibition experiments by MIF and SCD1 inhibitors support the hypothesis. These results suggest that the gene set is useful as a prognostic marker associated with tumor progression.

  9. Evening primrose oil treatment corrects reduced conduction velocity but not depletion of arachidonic acid in nerve from streptozotocin-induced diabetic rats.

    PubMed

    Kuruvilla, R; Peterson, R G; Kincaid, J C; Eichberg, J

    1998-09-01

    The effects of evening primrose oil (EPO) treatment, a source of gamma-linolenic acid, on the proportions of arachidonoyl-containing molecular species (ACMS) in sciatic nerve phosphatidylcholine and phosphatidylethanolamine were determined in conjunction with alterations in nerve conduction velocity. Normal and diabetic rats were either untreated or fed a dietary supplement containing isocalorically equivalent amounts of either EPO or corn oil for the duration of the experiment. After 8 weeks of streptozotocin-induced diabetes, nerve conduction velocity was reduced 16% and this deficit was prevented by either EPO or corn oil treatment. Neither EPO nor corn oil supplementation significantly increased the depressed proportions of ACMS. The level of the linoleoyl-containing molecular species, 16:0/18:2, was elevated in the phospholipids from untreated diabetic rats and was further increased by EPO treatment. These results are consistent with decreased activity of the delta6 desaturase that is required for arachidonic acid synthesis in vivo, but suggests that an accompanying deficit in the subsequent delta5 desaturase-catalyzed reaction may be rate-limiting. These findings indicate that maintenance of normal ACMS levels is not required for prevention of diminished nerve conduction velocity and suggest that other factors influenced by an altered polyunsaturated fatty acid pattern, such as metabolites of linoleic acid or gamma-linolenic acid other than arachidonic acid, the energy state of the nerve or the degree of membrane fluidity may contribute to impaired nerve conduction velocity in diabetic neuropathy.

  10. Characterization of the acute lactational response to trans-10, cis-12 conjugated linoleic acid.

    PubMed

    Harvatine, K J; Bauman, D E

    2011-12-01

    Trans-10, cis-12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis in the dairy cow. The decrease in milk fat yield during abomasal infusion of CLA reaches a nadir after 3 to 5 d. The acute responses to CLA were evaluated using 4 cows in a crossover design. Cows were milked with the aid of oxytocin every 4h from -28 to 80h and every 6h from 86 to 116h relative to the initiation of abomasal CLA infusion. An initial priming dose of 7.5g of CLA was given at time zero followed by infusion of 2.5g every 4h for 72h. Plasma CLA reached a near-steady-state concentration by 4h, and initial plasma enrichments were greatest in the triglyceride and nonesterified fatty acid fractions. Milk CLA concentration peaked at 6h and reached steady state by 22h. At termination of the infusion, decreases in milk CLA concentration and yield and plasma CLA concentration were best fit by a reciprocal-linear function. Milk fat percentage decreased progressively after 2h and was significant by 14h. Milk fatty acid profile was initially unchanged, but between 18 and 36h after initiation of the CLA dose the proportions of fatty acids progressively shifted, resulting in an increase in fatty acids >C16 and a decrease in fatty acids desaturase index were immediate, with a significant decrease by 6h and a near-maximal decrease by 10h. Thus, stearoyl desaturase enzyme was more acutely responsive to CLA than other enzymes in milk fat synthesis. The initial decrease in milk fat synthesis involved an equal depression of short- and long-chain fatty acid pathways and was followed thereafter by a more pronounced decrease in the synthesis of de novo fatty acids.

  11. Lipogenesis and stearoyl-CoA desaturase gene expression and enzyme activity in adipose tissue of short- and long-fed Angus and Wagyu steers fed corn- or hay-based diets.

    PubMed

    Chung, K Y; Lunt, D K; Kawachi, H; Yano, H; Smith, S B

    2007-02-01

    Angus and Wagyu steers consuming high-roughage diets exhibit large differences in adipose tissue fatty acid composition, but there are no differences in terminal measures of stearoyl-CoA desaturase (SCD) activity or gene expression. Also, adipose tissue lipids of cattle fed corn-based diets have greater MUFA:SFA ratios than cattle fed hay-based diets. We hypothesized that any changes in SCD gene expression and activity would precede similar changes in adipose tissue lipogenesis between short- and long-fed endpoints. Furthermore, changes in SCD activity and gene expression between production endpoints would differ between corn- and hay-fed steers and between Wagyu and Angus steers. Angus (n = 8) and Wagyu (n = 8) steers were fed a corn-based diet for 8 mo (short-fed; 16 mo of age) or 16 mo (long-fed; 24 mo of age), whereas another group of Angus (n = 8) and Wagyu (n = 8) steers was fed a hay-based diet for 12 mo (short-fed; 20 mo of age) or 20 mo (long-fed; 28 mo of age) to match the end point BW of the corn-fed steers. Acetate incorporation into lipids in vitro was greater (P < 0.01) in corn-fed steers than in hay-fed steers and tended (P = 0.06) to be greater in Wagyu than in Angus s.c. adipose tissue because the rate in Wagyu was twice that of Angus adipose tissue in the corn-fed, short-fed steers. There were diet x end point interactions for lipogenesis in i.m. and s.c. adipose tissues (both P < 0.01) because lipogenesis was 60 to 90% lower in the long-fed cattle than in short-fed cattle fed the corn-based diet. The greatest SCD enzyme activity in Angus s.c. adipose tissue was observed at 24 mo of age (corn-based diet), but activity in Wagyu adipose tissue was greatest at 28 mo of age (hay-based diet; breed x diet x end point interaction, P = 0.08). For short- vs. long-fed endpoints in Angus, s.c. adipose tissue SCD activity was less (hay diet) or the same (corn diet). Conversely, SCD gene expression was greatest in long-fed Wagyu steers fed the hay- or corn

  12. Dehydroepiandrosterone-sulphate replacement improves the human plasma fatty acid profile in plasma of obese women.

    PubMed

    Gómez-Santos, C; Larqué, E; Granero, E; Hernández-Morante, J J; Garaulet, M

    2011-12-11

    DHEA-S treatment is used as an anti-aging and anti-obesity hormone therapy in adults; however, it mechanisms of action are not clearly elucidated. The objective of the present work was to analyze the effect of a replacement therapy, which included a daily single oral dose of DHEA-S for three months, on the composition of human plasma fatty acids (FAs) in obese women. In the first study, a randomized, double-blind, placebo-controlled trial was conducted involving 61 postmenopausal women, who were assigned to receive 100mg/day of DHEA-S (n = 41) or placebo (n = 20) orally for 3 months. In a second study, the effect of DHEA-S treatment on postmenopausal obese women (n = 41) was compared to that in premenopausal obese women (n = 20). Blood samples were collected at the beginning and at the end of the treatment. Plasma FAs were analyzed by gas chromatography. DHEA-S treatment produced significant changes in plasma FAs of both post- and premenopausal women with a reduction of total saturated FAs (SFA) as well as an increase in n-6 polyunsaturated FA (PUFA). Particularly, in premenopausal women the DHEA-S treatment also increased the plasma n-3 PUFA percentage. Regarding estimation of desaturase activity, our data showed that Δ6-desaturase was significantly decreased in postmenopausal women after DHEA-S treatment, whereas Δ5-desaturase was increased in the premenopausal group. In conclusion, DHEA-S treatment in obese women modifies plasma FA composition towards a potentially better metabolic profile, mainly by decreasing SFA and increasing n-6 PUFA in both postmenopausal and premenopausal women.

  13. Effects of Oils Rich in Linoleic and α-Linolenic Acids on Fatty Acid Profile and Gene Expression in Goat Meat

    PubMed Central

    Ebrahimi, Mahdi; Rajion, Mohamed Ali; Goh, Yong Meng

    2014-01-01

    Alteration of the lipid content and fatty acid (FA) composition of foods can result in a healthier product. The aim of this study was to determine the effect of flaxseed oil or sunflower oil in the goat diet on fatty acid composition of muscle and expression of lipogenic genes in the semitendinosus (ST) muscle. Twenty-one entire male Boer kid goats were fed diets containing different levels of linoleic acid (LA) and α-linolenic acid (LNA) for 100 days. Inclusion of flaxseed oil increased (p < 0.05) the α-linolenic acid (C18:3n-3) concentration in the ST muscle. The diet high in α-linolenic acid (p < 0.05) decreased the arachidonic acid (C20:4n-6) and conjugated linolenic acid (CLA) c-9 t-11 content in the ST muscle. There was a significant (p < 0.05) upregulation of PPARα and PPARγ gene expression and downregulation of stearoyl-CoA desaturase (SCD) gene in the ST muscle for the high α-linolenic acid group compared with the low α-linolenic acid group. The results of the present study show that flaxseed oil as a source of α-linolenic acid can be incorporated into the diets of goats to enrich goat meat with n-3 fatty acids, upregulate the PPARα and PPARγ, and downregulate the SCD gene expression. PMID:25255382

  14. Dietary linseed oil in the maternal diet affects immunoglobulins, tissue fatty acid composition and expression of lipid metabolism-related genes in piglets.

    PubMed

    Chen, X L; Wang, N; Tian, M L; Wang, L; Liu, T; Zhang, X W; Shi, B M; Shan, A S

    2016-11-21

    This experiment investigated the effects of supplementing the maternal diet with linseed oil (LSO) and soya bean oil (SBO) on immunoglobulins, the fatty acid composition and hepatic expression of lipid metabolism-related genes in piglets. Multiparous sows (twenty-four per diet) were fed on diets containing a supplement of either SBO or LSO during last week of gestation and lactation. The results indicated that supplementation of maternal diet with LSO could improve the weaning weight of piglets and average daily gain (ADG) (p < 0.05). The concentration of immunoglobulin G (IgG) and immunoglobulin A (IgA) was enhanced in sow plasma, colostrum and milk by the addition of LSO (p < 0.05). In addition, the concentration of 18: 3n-3 fatty acids was higher in the milk of LSO sows. Meanwhile, maternal supplementation with LSO increased the levels of plasma IgG, IgA and the tissues n-3 polyunsaturated fatty acid (PUFA) in piglets (p < 0.05). Correspondingly, the mRNA expression levels of hepatic ∆5-desaturase (D5D) and ∆6-desaturase (D6D) were higher, and fatty acid synthase (FAS) was lower in piglets from LSO-fed sows when compared with that in the SBO group. In conclusion, LSO supplementation of the maternal diet increases immunoglobulins, modifies the fatty acid composition and affects the gene of D5D and D6D expression of piglets.

  15. Effect of sex hormones on plasma phospholipid fatty acid composition in intact rats and rats with bilaterally occluded carotid arteries.

    PubMed

    Petrović, S; Takić, M; Arsić, A; Vučić, V; Drakulić, D; Milošević, M; Glibetić, M

    2014-01-01

    The effects of 8-days treatment with 17alpha-estradiol (33.3 microg/kg) and progesterone (1.7 mg/kg) on plasma lipids and fatty acid composition of plasma phospholipids were examined in intact (INT) and bilaterally common carotid arteries occluded (BCO) male Wistar rats. Significant decrease of triglyceride level was found in BCO rats after the estradiol treatment. Both hormones elevated proportion of 18:1n-7 fatty acid in INT, but they failed to have such an effect in BCO. Estradiol increased 22:5n-3 and total n-3 polyunsaturated fatty acids (PUFA) in intact, and decreased 18:2n-6 in BCO rats. Significantly lower level of total n-3 was found in progesterone-treated than in estradiol-treated BCO rats. Given that n-3 PUFA have many beneficial effects on cell and tissue function, while n-6 PUFA have mostly the opposite effects, estradiol, rather than progesterone, was seen to improve plasma lipids and phospholipids FA profiles in INT and BCO animals. Estradiol significantly elevated the estimated activity of delta9-desaturases and progesterone of delta5-desaturase in BCO group, with no effects in INT rats.

  16. Modulation of lipid metabolism in glycyrrhizic acid-treated rats fed on a high-calorie diet and exposed to short or long-term stress.

    PubMed

    Yaw, Hui Ping; Ton, So Ha; Chin, Hsien-Fei; Karim, Muhammad Kaiser Abdul; Fernando, Hamish Alexander; Kadir, Khalid Abdul

    2015-01-01

    Stress and high-calorie diets increase the risk of developing metabolic syndrome. Glycyrrhizic acid (GA) has been shown to improve dyslipidaemia in rats fed on a high-calorie diet. This study aimed to examine the effects of GA on lipid metabolism in rats exposed to short- or long-term stress and on a high-calorie diet. The parameters examined included serum lipid profiles, serum free fatty acids and fatty acid profiles in tissues, and expression of peroxisome proliferator-activated receptors (PPAR), lipoprotein lipase (LPL), elongases and desaturases. Within the 14- or 28-day exposure groups, neither stress nor GA affected the lipid profile and serum free fatty acids. Stress did not affect PPAR-α expression in both the 14- and 28-day exposure groups. However, GA-treated rats from the former group had increased PPAR-α expression only in the kidney while all other tissues from the latter group were unaffected. Stress increased PPAR-γ expression in the heart of the 28-day exposure group but its expression was unaffected in all tissues of the 14-day exposure group. GA elevated PPAR-γ expression in the kidney and the skeletal muscles. Neither stress nor GA affected LPL expressions in all tissues from the 14-day exposure group but its expressions were elevated in the QF of the stressed rats and heart of the GA-treated rats of the 28-day exposure group. As for the elongases and desaturases in the liver, stress down-regulated ELOVL5 in the long-term exposure group while up-regulated ELOVL6 in the short-term exposure group while hepatic desaturases were unaffected by stress. Neither elongase nor desaturase expressions in the liver were affected by GA. This research is the first report of GA on lipid metabolism under stress and high-calorie diet conditions and the results gives evidence for the role of GA in ameliorating MetS via site-specific regulation of lipid metabolism gene expressions and modification of fatty acids.

  17. Tumor biology of non-metastatic stages of clear cell renal cell carcinoma; overexpression of stearoyl desaturase-1, EPO/EPO-R system and hypoxia-related proteins.

    PubMed

    Stoyanoff, Tania Romina; Rodríguez, Juan Pablo; Todaro, Juan Santiago; Espada, Joaquín Diego; Colavita, Juan Pablo Melana; Brandan, Nora Cristina; Torres, Adriana Mónica; Aguirre, María Victoria

    2016-10-01

    Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal carcinomas. There is great interest to know the molecular basis of the tumor biology of ccRCC that might contribute to a better understanding of the aggressive biological behavior of this cancer and to identify early biomarkers of disease. This study describes the relationship among proliferation, survival, and apoptosis with the expression of key molecules related to tumoral hypoxia (hypoxia-inducible factor (HIF)-1α, erythropoietin (EPO), vascular endothelial growth factor (VEGF)), their receptors (EPO-R, VEGFR-2), and stearoyl desaturase-1 (SCD-1) in early stages of ccRCC. Tissue samples were obtained at the Urology Unit of the J.R. Vidal Hospital (Corrientes, Argentina), from patients who underwent radical nephrectomy for renal cancer between 2011 and 2014. Four experimental groups according to pathological stage and nuclear grade were organized: T1G1 (n = 6), T2G1 (n = 4), T1G2 (n = 7), and T2G2 (n = 7). The expression of HIF-1α, EPO, EPO-R, VEGF, VEGFR-2, Bcl-xL, and SCD-1 were evaluated by immunohistochemistry, Western blotting, and/or RT-PCR. Apoptosis was assessed by the TUNEL in situ assay, and tumor proliferation was determined by Ki-67 immunohistochemistry. Data revealed that HIF-1α, EPO, EPO-R, VEGF, and VEGF-R2 were overexpressed in most samples. The T1G1 group showed the highest EPO levels, approximately 200 % compared with distal renal tissue. Bcl-xL overexpression was concomitant with the enhancement of proliferative indexes. SCD-1 expression increased with the tumor size and nuclear grade. Moreover, the direct correlations observed between SCD-1/HIF-1α and SCD-1/Ki-67 increments suggest a link among these molecules, which would determine tumor progression in early stages of ccRCC. Our results demonstrate the relationship among proliferation, survival, and apoptosis with the expression of key molecules related to tumoral hypoxia (HIF-1α, EPO, VEGF), their

  18. Fatty acid composition and properties of the liver microsomal membrane of rats fed diets enriched with cholesterol.

    PubMed

    Muriana, F J; Vazquez, C M; Ruiz-Gutierrez, V

    1992-10-01

    Male rats were fed diets containing olive (OO) or evening primrose (EPO) oil (10% w/w), with or without added cholesterol (1% w/w). After 6-week feeding, the lipid and fatty acid compositions, fluidity, and fatty acid desaturating and cholesterol biosynthesis/esterification related enzymes of liver microsomes were determined. Both the OO and EPO diets, without added cholesterol, increased the contents of oleic and arachidonic acids, respectively, of rat liver microsomes. The results were consistent with the increases in delta 9 and delta 6 desaturation of n-6 essential fatty acids and the lower microviscosity in the EPO group. Dietary cholesterol led to an increase in the cholesterol content of liver microsomes as well as that of phosphatidylcholine (PC). The cholesterol/phospholipid and PC/PE (phosphatidylethanolamine) ratios were also elevated. Fatty acid composition changes were expressed as the accumulation of monounsaturated fatty acids, with accompanying milder depletion of saturated fatty acids in rat liver microsomes. In addition, the arachidonic acid content was lowered, with a concomitant increase in linoleic acid, which led to a significant decrease in the 20:4/18:2 ratio in comparison to in animals fed the cholesterol-free diets. Cholesterol feeding also increased delta 9 desaturase activity as well as membrane microviscosity, whereas it decreased delta 6 and delta 5 desaturase activities. There was a very strong correlation between fluidity and the unsaturation index reduction in the membrane. Furthermore, the activity of hydroxymethylglutaryl-CoA reductase increased and the activity of acyl-CoA:cholesterol acyltransferase decreased in liver microsomes from both cholesterol-fed groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Effect of Delta 9–Stearoyl-ACP-Desaturase-C mutants in a high oleic background on soybean seed oil composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] oil typically contains 2-4% stearic acid. Oil with at least 20% stearic acid is desirable because of its baking properties and health profile. This study identifies two new sources of high stearic acid and evaluates the interaction of high stearic and oleic acid al...

  20. Effects of abomasal infusion of conjugated linoleic acids, Sterculia foetida oil, and fish oil on production performance and the extent of fatty acid Δ⁹-desaturation in dairy cows.

    PubMed

    Dallaire, M P; Taga, H; Ma, L; Corl, B A; Gervais, R; Lebeuf, Y; Richard, F J; Chouinard, P Y

    2014-10-01

    The purpose of this study was to determine the effects of conjugated linoleic acid (CLA), Sterculia foetida oil (STO), and fish oil (FO) on milk yield and composition, milk FA profile, Δ(9)-desaturation activity, and mammary expression of 2 isoforms of stearoyl-coenzyme A desaturase (SCD-1 and SCD-5) in lactating dairy cows. Eight multiparous Holstein cows (69 ± 13 d postpartum) were used in a double 4 × 4 Latin square design with 28-d periods. For the first 14 d of each period, cows received an abomasal infusion of (1) 406 g of a saturated fatty acid (SFA) supplement (112 g of 16:0 + 230 g of 18:0) used as a control (CTL), (2) 36 g of a CLA supplement (13.9 g of trans-10,cis-12 18:2) + 370 g of SFA, (3) 7 g of STO (3.1g of 19:1 cyclo) + 399 g of SFA, or (4) 406 g of FO (55.2 g of cis-5,-8,-11,-14,-17 20:5 + 59.3 g of cis-4,-7,-10,-13,-16,-19 22:6). Infusions were followed by a 14-d washout interval. Compared with CTL, STO decreased milk yield from 38.0 to 33.0 kg/d, and increased milk fat concentration from 3.79 to 4.45%. Milk fat concentration was also decreased by CLA (2.23%) and FO (3.34%). Milk fat yield was not affected by STO (1,475 g/d) compared with CTL (1,431 g/d), but was decreased by CLA (774 g/d) and FO (1,186 g/d). Desaturase indices for 10:0, 12:0, and 20:0 were decreased, whereas the extent of desaturation of 14:0, 16:0, 17:0, and 18:0 was not affected by CLA treatment compared with CTL. Infusion of STO significantly decreased all calculated desaturase indices compared with CTL; the 14:0 index was reduced by 80.7%. Infusion of FO decreased the desaturase indices for 10:0, 14:0, 20:0, trans-11 18:1, and 18:0. The effect of FO on the 14:0 index indicates a decrease in apparent Δ(9)-desaturase activity of 30.2%. Compared with CTL, mammary mRNA abundance of SCD-1 was increased by STO (+30%) and decreased by CLA (-24%), whereas FO had no effect. No effect was observed on mRNA abundance of SCD-5. In conclusion, abomasal infusion of CLA, STO, and FO

  1. Biosynthesis of gamma-linolenic acid in developing seeds of borage (Borago officinalis L.).

    PubMed

    Galle, A M; Joseph, M; Demandre, C; Guerche, P; Dubacq, J P; Oursel, A; Mazliak, P; Pelletier, G; Kader, J C

    1993-08-20

    delta 6-desaturation of [14C]linoleoyl-CoA or [14C]oleoyl-CoA leading to the synthesis of gamma-linolenic acid was studied in vitro with microsomal fractions from developing seeds of Borago officinalis. Time course of the reaction, effects of protein and precursor concentrations and nucleotide requirements were examined. These parameters allowed us to improve the in vitro delta 6-desaturation assay. We observed that the precursors were acylated mainly in phosphatidylcholine, diacylglycerol and triacylglycerol, and then desaturated. NADH was absolutely required when [14C]oleoyl-CoA was the precursor, but not when [14C]linoleoyl-CoA was the precursor although it stimulated the reaction. The in vitro delta 6-desaturase activity was found mainly in phosphatidylcholine, associated with enriched endoplasmic reticulum membranes (ER) from embryos. No activity was observed in ER from seed coat or seedling. During maturation of the seeds, delta 6-desaturase reached its highest activity 14 to 16 days after pollination.

  2. Enhancing the accumulation of omega-3 long chain polyunsaturated fatty acids in transgenic Arabidopsis thaliana via iterative metabolic engineering and genetic crossing.

    PubMed

    Ruiz-López, Noemi; Haslam, Richard P; Venegas-Calerón, Mónica; Li, Tianbi; Bauer, Joerg; Napier, Johnathan A; Sayanova, Olga

    2012-12-01

    The synthesis and accumulation of long chain polyunsaturated fatty acids such as eicosapentaenoic acid has previously been demonstrated in the seeds of transgenic plants. However, the obtained levels are relatively low, indicating the need for further studies and the better definition of the interplay between endogenous lipid synthesis and the non-native transgene-encoded activities. In this study we have systematically compared three different transgenic configurations of the biosynthetic pathway for eicosapentaenoic acid, using lipidomic profiling to identify metabolic bottlenecks. We have also used genetic crossing to stack up to ten transgenes in Arabidopsis. These studies indicate several potential approaches to optimize the accumulation of target fatty acids in transgenic plants. Our data show the unexpected channeling of heterologous C20 polyunsaturated fatty acids into minor phospholipid species, and also the apparent negative metabolic regulation of phospholipid-dependent Δ6-desaturases. Collectively, this study confirms the benefits of iterative approaches to metabolic engineering of plant lipid synthesis.

  3. Maternal high-fat-diet programs rat offspring liver fatty acid metabolism.

    PubMed

    Seet, Emily L; Yee, Jennifer K; Jellyman, Juanita K; Han, Guang; Ross, Michael G; Desai, Mina

    2015-06-01

    In offspring exposed in utero to a maternal diet high in fat (HF), we have previously demonstrated that despite similar birth weights, HF adult offspring at 6 months of age had significantly higher body weights, greater adiposity, and increased triacylglycerol (TAG) levels as compared to controls. We hypothesized that a maternal HF diet predisposes to offspring adiposity via a programmed increase in the synthesis of monounsaturated fatty acids in the liver and hence increased substrate availability for liver TAG synthesis. We further hypothesized that programmed changes in offspring liver fatty acid metabolism are associated with increased liver expression of the lipogenic enzyme stearoyl-CoA desaturase-1 (SCD-1). Female rats were maintained on a HF diet rich in monounsaturated fatty acids (MUFA) prior to and throughout pregnancy and lactation. After birth, newborns were nursed by the same dam, and all offspring were weaned to control diet. Plasma and liver fatty acid compositions were determined using gas chromatography/mass spectrometry. Fatty acid C16 desaturation indices of palmitoleic/palmitic and (vaccenic + palmitoleic)/palmitic and the C18 desaturation index of oleic/stearic were calculated. Liver protein abundance of SCD-1 was analyzed in newborns and adult offspring. Plasma and liver C16 desaturation indices were decreased in HF newborns, but increased in the adult offspring. Liver SCD-1 expression was increased in the HF adult offspring. These data show that the maternal HF diet during pregnancy and lactation increases offspring liver SCD-1 protein abundance and alters the liver C16 desaturase pathway.

  4. Novel fatty acid elongases and their use for the reconstitution of docosahexaenoic acid biosynthesis.

    PubMed

    Meyer, Astrid; Kirsch, Helene; Domergue, Frédéric; Abbadi, Amine; Sperling, Petra; Bauer, Jörg; Cirpus, Petra; Zank, Thorsten K; Moreau, Hervé; Roscoe, Thomas J; Zähringer, Ulrich; Heinz, Ernst

    2004-10-01

    In algae, the biosynthesis of docosahexaenoic acid (22:6omega3; DHA) proceeds via the elongation of eicosapentaenoic acid (20:5omega3; EPA) to 22:5omega3, which is required as a substrate for the final Delta4 desaturation. To isolate the elongase specific for this step, we searched expressed sequence tag and genomic databases from the algae Ostreococcus tauri and Thalassiosira pseudonana, from the fish Oncorhynchus mykiss, from the frog Xenopus laevis, and from the sea squirt Ciona intestinalis using as a query the elongase sequence PpPSE1 from the moss Physcomitrella patens. The open reading frames of the identified elongase candidates were expressed in yeast for functional characterization. By this, we identified two types of elongases from O. tauri and T. pseudonana: one specific for the elongation of (Delta6-)C18-PUFAs and one specific for (Delta5-)C20-PUFAs, showing highest activity with EPA. The clones isolated from O. mykiss, X. laevis, and C. intestinalis accepted both C18- and C20-PUFAs. By coexpression of the Delta6- and Delta5-elongases from T. pseudonana and O. tauri, respectively, with the Delta5- and Delta4-desaturases from two other algae we successfully implemented DHA synthesis in stearidonic acid-fed yeast. This may be considered an encouraging first step in future efforts to implement this biosynthetic sequence into transgenic oilseed crops.

  5. Trans-10,cis-12-CLA-caused lipodystrophy is associated with profound changes of fatty acid profiles of liver, white adipose tissue and erythrocytes in mice: possible link to tissue-specific alterations of fatty acid desaturation.

    PubMed

    Jaudszus, Anke; Moeckel, Peter; Hamelmann, Eckard; Jahreis, Gerhard

    2010-01-01

    Dietary supplementation with conjugated linoleic acid (CLA) has been shown to reduce body fat mass. To investigate the effects of individual CLA isomers on the fatty acid profiles of lipogenic (liver and white adipose) and lipid sensitive (erythrocyte) tissues, BALB/c mice were fed with 1 of 2 diets supplemented with either a c9,t11-CLA-enriched and t10,c12-CLA-free or a CLA-mixture containing both isomers in equal amounts (1% w/w of the diet) for 5 weeks. A control group was fed with a diet enriched in sunflower oil to energy balance the CLA. Compared to the t10,c12-CLA-free and the control diets, we observed a significant reduction of adipose tissue accompanied by fatty livers in the CLA-mix-fed group. These alterations in body fat distribution entailed a conspicuous shift of the fatty acid profiles of adipose tissue and livers. Liver enlargement was mainly caused by accumulation of C18 monoenes that accounted for 67 ± 1% of total fatty acid methyl esters. The significant reduction of the 18:0/18:1 desaturation index in the liver upon CLA-mix diet indicated high stearoyl-CoA desaturase activity. In contrast, reduction in white adipose tissue was largely driven by percental reduction of monounsaturated fatty acids (p ≤ 0.001). 16:0/ 16:1 and 18:0/18:1 desaturation indices for white adipose tissue significantly increased, suggesting an inhibition of stearoyl-CoA desaturase upon CLA-mix diet. The fatty acid profile of the erythrocytes widely reflected that of livers, depending on the supplemented diet. These profound changes in fatty acid composition of lipogenic organs due to t10,c12-CLA intake may be the consequence of functional alterations of lipid metabolism.

  6. Functional Diversity in Fungal Fatty Acid Synthesis

    PubMed Central

    Blacklock, Brenda J.; Scheffler, Brian E.; Shepard, Michael R.; Jayasuriya, Naomi; Minto, Robert E.

    2010-01-01

    Acetylenic specialized metabolites containing one or more carbon-carbon triple bonds are widespread, being found in fungi, vascular and lower plants, marine sponges and algae, and insects. Plants, moss, and most recently, insects, have been shown to employ an energetically difficult, sequential dehydrogenation mechanism for acetylenic bond formation. Here, we describe the cloning and heterologous expression in yeast of a linoleoyl 12-desaturase (acetylenase) and a bifunctional desaturase with Δ12-/Δ14-regiospecificity from the Pacific golden chanterelle. The acetylenase gene, which is the first identified from a fungus, is phylogenetically distinct from known plant and fungal desaturases. Together, the bifunctional desaturase and the acetylenase provide the enzymatic activities required to drive oleate through linoleate to crepenynate and the conjugated enyne (14Z)-dehydrocrepenynate, the branchpoint precursors to a major class of acetylenic natural products. PMID:20606235

  7. Milk fat globules: fatty acid composition, size and in vivo regulation of fat liquidity.

    PubMed

    Timmen, H; Patton, S

    1988-07-01

    Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer short-chain acids, -5.9%, less stearic acid, -22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences are consistent with alternative use of short-chain acids or oleic acid converted from stearic acid to maintain liquidity at body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl-CoA desaturase (EC 1.14.99.5), which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols are discussed.

  8. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids

    PubMed Central

    Watts, Jennifer L.

    2016-01-01

    The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids. PMID:26848697

  9. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids.

    PubMed

    Watts, Jennifer L

    2016-02-02

    The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids.

  10. A Mutant of Arabidopsis with Increased Levels of Stearic Acid.

    PubMed Central

    Lightner, J.; Wu, J.; Browse, J.

    1994-01-01

    A mutation at the fab2 locus of Arabidopsis caused increased levels of stearate in leaves. The increase in leaf stearate in fab2 varied developmentally, and the largest increase occurred in young leaves, where stearate accounted for almost 20% of total leaf fatty acids. The fatty acid composition of leaf lipids isolated from the fab2 mutant showed increased stearate in all the major glycerolipids of both the chloroplast and extrachloroplast membranes. Although the stearate content was increased, the fab2 mutant still contained abundant amounts of 18:1, 18:2, and 18:3 fatty acids. These results are consistent with the expectations for a mutation partially affecting the action of the stromal stearoyl-acyl carrier protein desaturase. Positional analysis indicated that the extra 18:0 is excluded with high specificity from the sn-2 position of both chloroplast and extrachloroplast glycerolipids. Although stearate content was increased in all the major leaf membrane lipids, the amount of increase varied considerably among the different lipids, from a high of 25% of fatty acids in phosphatidylcholine to a low of 2.9% of fatty acids in monogalactosyldiacylglycerol. PMID:12232421

  11. The TOC159 mutant of Arabidopsis thaliana accumulates altered levels of saturated and polyunsaturated fatty acids.

    PubMed

    Afitlhile, Meshack; Fry, Morgan; Workman, Samantha

    2015-02-01

    We evaluated whether the TOC159 mutant of Arabidopsis called plastid protein import 2-2 (ppi2-2) accumulates normal levels of fatty acids, and transcripts of fatty acid desaturases and galactolipid synthesis enzymes. The ppi2-2 mutant accumulates decreased pigments and total fatty acid content. The MGD1 gene was downregulated and the mutant accumulates decreased levels of monogalactosyldiacylglycerol (MGDG) and 16:3, which suggests that the prokaryotic pathway was impaired in the mutant. The HY5 gene, which encodes long hypocotyl5 transcription factor, was upregulated in the mutant. The DGD1 gene, an HY5 target was marginally increased and the mutant accumulates digalactosyldiacylglycerol at the control level. The mutant had increased expression of 3-ketoacyl-ACP synthase II gene, which encodes a plastid enzyme that elongates 16:0 to 18:0. Interestingly, glycerolipids in the mutant accumulate increased levels of 18:0. A gene that encodes stearoyl-ACP desaturase (SAD) was expressed at the control level and 18:1 was increased, which suggest that SAD may be strongly regulated at the posttranscriptional level. The molar ratio of MGDG to bilayer forming plastid lipids was decreased in the cold-acclimated wild type but not in the ppi2-2 mutant. This indicates that the mutant was unresponsive to cold-stress, and is consistent with increased levels of 18:0, and decreased 16:3 and 18:3 in the ppi2-2 mutant. Overall, these data indicate that a defective Toc159 receptor impaired the synthesis of MGDG, and affected desaturation of 16 and 18-carbon fatty acids. We conclude that expression of the MGD1 gene and synthesis of MGDG are tightly linked to plastid biogenesis.

  12. Selective modification of rat hepatic microsomal fatty acid chain elongation and desaturation by fibrates: relationship with peroxisome proliferation.

    PubMed

    Alegret, M; Cerqueda, E; Ferrando, R; Vázquez, M; Sánchez, R M; Adzet, T; Merlos, M; Laguna, J C

    1995-04-01

    1. The time-course of the effect of clofibrate (CFB), bezafibrate (BFB) and gemfibrozil (GFB) on lipid plasma levels and palmitoyl-, palmitoleoyl- and gamma-linolenoyl-CoA elongase, delta-9, delta-6 and delta-5 desaturase activities, and microsomal electron transport chains, as well as the correlation with the peroxisomal proliferation phenomenon have been studied in male Sprague-Dawley rats. 2. As reported in our previous work, the three drugs behave as peroxisomal proliferators (the order of potency was BFB > CFB > or = GFB) and induced a clear reduction in both plasma cholesterol and triglyceride levels. 3. Palmitoyl-CoA elongation activity was increased by the three drugs (BFB = GFB > CFB), whereas palmitoleoyl-CoA elongation activity was only enhanced by GFB. Elongation activity was not modified by fibrates when gamma-linolenoyl-CoA was used as substrate. These results are in accordance with the existence of three different elongation systems for saturated, mono- and polyunsaturated fatty acids. 4. delta-9, delta-6 and delta-5 desaturase activities were increased by the three fibrates, with an order of potency BFB > CFB = GFB for delta-9 and delta-5, and GFB > BFB = CFB for delta-6. 5. Of the enzyme activities integrated in the microsomal electron transport chains, NADH cytochrome b5 reductase was not affected by fibrate treatment, NADPH cytochrome c reductase activity was enhanced (BFB = GFB > CFB), whereas NADH cytochrome c reductase activity was reduced by CFB and BFB. 6. The increase in Delta-9 and Delta-5 desaturase activities was highly dependent on the peroxisomal proliferation phenomena, whereas the increase in Delta-6 desaturase activity and the decrease in NADH cytochromec reductase was mainly independent. The modifications of palmitoyl-CoA elongase and NADPH cytochrome c reductase activities, as well as plasma lipid levels, were partially correlated with peroxisomal beta-oxidation, but the r2 values obtained point to the existence of additional

  13. Identification of genes and pathways involved in the synthesis of Mead acid (20:3n-9), an indicator of essential fatty acid deficiency.

    PubMed

    Ichi, Ikuyo; Kono, Nozomu; Arita, Yuka; Haga, Shizuka; Arisawa, Kotoko; Yamano, Misato; Nagase, Mana; Fujiwara, Yoko; Arai, Hiroyuki

    2014-01-01

    In mammals, 5,8,11-eicosatrienoic acid (Mead acid, 20:3n-9) is synthesized from oleic acid during a state of essential fatty acid deficiency (EFAD). Mead acid is thought to be produced by the same enzymes that synthesize arachidonic acid and eicosapentaenoic acid, but the genes and the pathways involved in the conversion of oleic acid to Mead acid have not been fully elucidated. The levels of polyunsaturated fatty acids in cultured cells are generally very low compared to those in mammalian tissues. In this study, we found that cultured cells, such as NIH3T3 and Hepa1-6 cells, have significant levels of Mead acid, indicating that cells in culture are in an EFAD state under normal culture conditions. We then examined the effect of siRNA-mediated knockdown of fatty acid desaturases and elongases on the level of Mead acid, and found that knockdown of Elovl5, Fads1, or Fads2 decreased the level of Mead acid. This and the measured levels of possible intermediate products for the synthesis of Mead acid such as 18:2n-9, 20:1n-9 and 20:2n-9 in the knocked down cells indicate two pathways for the synthesis of Mead acid: pathway 1) 18:1n-9→(Fads2)→18:2n-9→(Elovl5)→20:2n-9→(Fads1)→20:3n-9 and pathway 2) 18:1n-9→(Elovl5)→20:1n-9→(Fads2)→20:2n-9→(Fads1)→20:3n-9.

  14. Liver Fatty Acid Composition and Inflammation in Mice Fed with High-Carbohydrate Diet or High-Fat Diet

    PubMed Central

    da Silva-Santi, Lorena Gimenez; Antunes, Marina Masetto; Caparroz-Assef, Silvana Martins; Carbonera, Fabiana; Masi, Laureane Nunes; Curi, Rui; Visentainer, Jesuí Vergílio; Bazotte, Roberto Barbosa

    2016-01-01

    Both high-carbohydrate diet (HCD) and high-fat diet (HFD) modulate liver fat accumulation and inflammation, however, there is a lack of data on the potential contribution of carbohydrates and lipids separately. For this reason, the changes in liver fatty acid (FA) composition in male Swiss mice fed with HCD or HFD were compared, at the time points 0 (before starting the diets), and after 7, 14, 28 or 56 days. Activities of stearoyl-CoA desaturase-1 (SCD-1), ∆-6 desaturase (D6D), elongases and de novo lipogenesis (DNL) were estimated. Liver mRNA expression of acetyl-CoA carboxylase 1 (ACC1) was evaluated as an additional indicator of the de novo lipogenesis. Myeloperoxidase activity, nitric oxide (NO) production, and mRNA expressions of F4/80, type I collagen, interleukin (IL)-6, IL-1β, IL-10, and tumor necrosis factor-α (TNF-α) were measured as indication of the liver inflammatory state. The HCD group had more intense lipid deposition, particularly of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). This group also showed higher DNL, SCD-1, and D6D activities associated with increased NO concentration, as well as myeloperoxidase activity. Livers from the HFD group showed higher elongase activity, stored more polyunsaturated fatty acids (PUFAs) and had a lower omega-6/omega-3 fatty acid (n-6/n-3) ratio. In conclusion, liver lipid accumulation, fatty acids (FA) composition and inflammation were modulated by the dietary composition of lipids and carbohydrates. The HCD group had more potent lipogenic and inflammatory effects in comparison with HFD. PMID:27801862

  15. Liver Fatty Acid Composition and Inflammation in Mice Fed with High-Carbohydrate Diet or High-Fat Diet.

    PubMed

    da Silva-Santi, Lorena Gimenez; Antunes, Marina Masetto; Caparroz-Assef, Silvana Martins; Carbonera, Fabiana; Masi, Laureane Nunes; Curi, Rui; Visentainer, Jesuí Vergílio; Bazotte, Roberto Barbosa

    2016-10-29

    Both high-carbohydrate diet (HCD) and high-fat diet (HFD) modulate liver fat accumulation and inflammation, however, there is a lack of data on the potential contribution of carbohydrates and lipids separately. For this reason, the changes in liver fatty acid (FA) composition in male Swiss mice fed with HCD or HFD were compared, at the time points 0 (before starting the diets), and after 7, 14, 28 or 56 days. Activities of stearoyl-CoA desaturase-1 (SCD-1), ∆-6 desaturase (D6D), elongases and de novo lipogenesis (DNL) were estimated. Liver mRNA expression of acetyl-CoA carboxylase 1 (ACC1) was evaluated as an additional indicator of the de novo lipogenesis. Myeloperoxidase activity, nitric oxide (NO) production, and mRNA expressions of F4/80, type I collagen, interleukin (IL)-6, IL-1β, IL-10, and tumor necrosis factor-α (TNF-α) were measured as indication of the liver inflammatory state. The HCD group had more intense lipid deposition, particularly of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). This group also showed higher DNL, SCD-1, and D6D activities associated with increased NO concentration, as well as myeloperoxidase activity. Livers from the HFD group showed higher elongase activity, stored more polyunsaturated fatty acids (PUFAs) and had a lower omega-6/omega-3 fatty acid (n-6/n-3) ratio. In conclusion, liver lipid accumulation, fatty acids (FA) composition and inflammation were modulated by the dietary composition of lipids and carbohydrates. The HCD group had more potent lipogenic and inflammatory effects in comparison with HFD.

  16. Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene

    PubMed Central

    Mihálik, Daniel; Klčová, Lenka; Ondreičková, Katarína; Hudcovicová, Martina; Gubišová, Marcela; Klempová, Tatiana; Čertík, Milan; Pauk, János; Kraic, Ján

    2015-01-01

    The artificial gene D6D encoding the enzyme ∆6desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T0 and T1 generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%–0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T1 generation as well as in immature and mature grains of the T2 generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%–1.40% (v/v) and 0%–1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat. PMID:26694368

  17. Quantitative trait loci with additive effects on palatability and fatty acid composition of meat in a Wagyu-Limousin F2 population.

    PubMed

    Alexander, L J; Macneil, M D; Geary, T W; Snelling, W M; Rule, D C; Scanga, J A

    2007-10-01

    A whole-genome scan was conducted on 328 F(2) progeny in a Wagyu x Limousin cross to identify quantitative trait loci (QTL) affecting palatability and fatty acid composition of beef at an age-constant endpoint. We have identified seven QTL on five chromosomes involved in lipid metabolism and tenderness. None of the genes encoding major enzymes involved in fatty acid metabolism, such as fatty acid synthase (FASN), acetyl-CoA carboxylase alpha (ACACA), solute carrier family 2 (facilitated glucose transporter) member 4 (SLC2A4), stearoyl-CoA desaturase (SCD) and genes encoding the subunits of fatty acid elongase, was located in these QTL regions. The present study may lead to a better-tasting and healthier product for consumers through improved selection for palatability and lipid content of beef.

  18. Hexadecenoic Fatty Acid Isomers in Human Blood Lipids and Their Relevance for the Interpretation of Lipidomic Profiles

    PubMed Central

    Sansone, Anna; Tolika, Evanthia; Louka, Maria; Sunda, Valentina; Deplano, Simone; Melchiorre, Michele; Anagnostopoulos, Dimitrios; Chatgilialoglu, Chryssostomos; Formisano, Cesare; Di Micco, Rosa; Faraone Mennella, Maria Rosaria; Ferreri, Carla

    2016-01-01

    Monounsaturated fatty acids (MUFA) are emerging health biomarkers, and in particular the ratio between palmitoleic acid (9cis-16:1) and palmitic acid (16:0) affords the delta-9 desaturase index that is increased in obesity. Recently, other positional and geometrical MUFA isomers belonging to the hexadecenoic family (C16 MUFA) were found in circulating lipids, such as sapienic acid (6cis-16:1), palmitelaidic acid (9trans-16:1) and 6trans-16:1. In this work we report: i) the identification of sapienic acid as component of human erythrocyte membrane phospholipids with significant increase in morbidly obese patients (n = 50) compared with age-matched lean controls (n = 50); and ii) the first comparison of erythrocyte membrane phospholipids (PL) and plasma cholesteryl esters (CE) in morbidly obese patients highlighting that some of their fatty acid levels have opposite trends: increases of both palmitic and sapienic acids with the decrease of linoleic acid (9cis,12cis-18:2, omega-6) in red blood cell (RBC) membrane PL were reversed in plasma CE, whereas the increase of palmitoleic acid was similar in both lipid species. Consequentially, desaturase enzymatic indexes gave different results, depending on the lipid class used for the fatty acid content. The fatty acid profile of morbidly obese subjects also showed significant increases of stearic acid (C18:0) and C20 omega-6, as well as decreases of oleic acid (9cis-18:1) and docosahexaenoic acid (C22:6 omega-3) as compared with lean healthy controls. Trans monounsaturated and polyunsaturated fatty acids were also measured and found significantly increased in both lipid classes of morbidly obese subjects. These results highlight the C16 MUFA isomers as emerging metabolic marker provided that the assignment of the double bond position and geometry is correctly performed, thus identifying the corresponding lipidomic pathway. Since RBC membrane PL and plasma CE have different fatty acid trends, caution must also be used in the

  19. Saturated phosphatidic acids mediate saturated fatty acid-induced vascular calcification and lipotoxicity.

    PubMed

    Masuda, Masashi; Miyazaki-Anzai, Shinobu; Keenan, Audrey L; Okamura, Kayo; Kendrick, Jessica; Chonchol, Michel; Offermanns, Stefan; Ntambi, James M; Kuro-O, Makoto; Miyazaki, Makoto

    2015-10-26

    Recent evidence indicates that saturated fatty acid-induced (SFA-induced) lipotoxicity contributes to the pathogenesis of cardiovascular and metabolic diseases; however, the molecular mechanisms that underlie SFA-induced lipotoxicity remain unclear. Here, we have shown that repression of stearoyl-CoA desaturase (SCD) enzymes, which regulate the intracellular balance of SFAs and unsaturated FAs, and the subsequent accumulation of SFAs in vascular smooth muscle cells (VSMCs), are characteristic events in the development of vascular calcification. We evaluated whether SMC-specific inhibition of SCD and the resulting SFA accumulation plays a causative role in the pathogenesis of vascular calcification and generated mice with SMC-specific deletion of both Scd1 and Scd2. Mice lacking both SCD1 and SCD2 in SMCs displayed severe vascular calcification with increased ER stress. Moreover, we employed shRNA library screening and radiolabeling approaches, as well as in vitro and in vivo lipidomic analysis, and determined that fully saturated phosphatidic acids such as 1,2-distearoyl-PA (18:0/18:0-PA) mediate SFA-induced lipotoxicity and vascular calcification. Together, these results identify a key lipogenic pathway in SMCs that mediates vascular calcification.

  20. Human colon cell culture models of different transformation stages to assess conjugated linoleic acid and conjugated linolenic acid metabolism: Challenges and chances.

    PubMed

    Degen, Christian; Habermann, Nina; Piegholdt, Stefanie; Glei, Michael; Jahreis, Gerhard

    2012-09-01

    Both cellular transformation status and cell culture conditions affect fatty acid metabolism. Hence, the incorporation and metabolism of c9,t11-CLA (conjugated linoleic acid) and other CFAs (conjugated fatty acids) were compared in colon cells (LT-97, adenoma; HT-29, adenocarcinoma). Growth inhibition by CFA in LT-97 cells was assessed via the DAPI (4',6-diamidino-2-phenylindole dihydrochloride) assay. Basal gene expression of desaturases (Δ5, Δ6 and Δ9) and elongases (1, 2, 5 and 6) was determined in LT-97 using PCR. Analysis of cellular fatty acids revealed a 2-fold higher incorporation of c9,t11-CLA (40 and 80μM) in HT-29 cells compared to LT-97 cells. The β-oxidized and elongated conjugated dienoic (CD) fatty acids differed by 8-fold (CD-C16:2/CD-C20:2; HT-29: 8:1; LT-97: 1:1). Notably, LT-97 cells were shown to convert conjugated linolenic acid (CLnA) to CLA. Moreover, LT-97 cells revealed no basal expression of elongase 2. CLnA caused stronger growth inhibition (≤80μM) compared to CLA (200μM). The results indicate that LT-97 cells represent a superior model to carry out elongation and desaturation studies of unsaturated and conjugated fatty acids compared to HT-29 cells. Nevertheless, further in-depth metabolic and transcriptomic analyses are required to confirm this suggestion.

  1. Selective modification of rat hepatic microsomal fatty acid chain elongation and desaturation by fibrates: relationship with peroxisome proliferation.

    PubMed Central

    Alegret, M; Cerqueda, E; Ferrando, R; Vázquez, M; Sánchez, R M; Adzet, T; Merlos, M; Laguna, J C

    1995-01-01

    1. The time-course of the effect of clofibrate (CFB), bezafibrate (BFB) and gemfibrozil (GFB) on lipid plasma levels and palmitoyl-, palmitoleoyl- and gamma-linolenoyl-CoA elongase, delta-9, delta-6 and delta-5 desaturase activities, and microsomal electron transport chains, as well as the correlation with the peroxisomal proliferation phenomenon have been studied in male Sprague-Dawley rats. 2. As reported in our previous work, the three drugs behave as peroxisomal proliferators (the order of potency was BFB > CFB > or = GFB) and induced a clear reduction in both plasma cholesterol and triglyceride levels. 3. Palmitoyl-CoA elongation activity was increased by the three drugs (BFB = GFB > CFB), whereas palmitoleoyl-CoA elongation activity was only enhanced by GFB. Elongation activity was not modified by fibrates when gamma-linolenoyl-CoA was used as substrate. These results are in accordance with the existence of three different elongation systems for saturated, mono- and polyunsaturated fatty acids. 4. delta-9, delta-6 and delta-5 desaturase activities were increased by the three fibrates, with an order of potency BFB > CFB = GFB for delta-9 and delta-5, and GFB > BFB = CFB for delta-6. 5. Of the enzyme activities integrated in the microsomal electron transport chains, NADH cytochrome b5 reductase was not affected by fibrate treatment, NADPH cytochrome c reductase activity was enhanced (BFB = GFB > CFB), whereas NADH cytochrome c reductase activity was reduced by CFB and BFB.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7606338

  2. Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids

    PubMed Central

    Berquin, Isabelle M.; Min, Younong; Wu, Ruping; Wu, Jiansheng; Perry, Donna; Cline, J. Mark; Thomas, Mike J.; Thornburg, Todd; Kulik, George; Smith, Adrienne; Edwards, Iris J.; D’Agostino, Ralph; Zhang, Hao; Wu, Hong; Kang, Jing X.; Chen, Yong Q.

    2007-01-01

    Although a causal role of genetic alterations in human cancer is well established, it is still unclear whether dietary fat can modulate cancer risk in a predisposed population. Epidemiological studies suggest that diets rich in omega-3 polyunsaturated fatty acids reduce cancer incidence. To determine the influence of fatty acids on prostate cancer risk in animals with a defined genetic lesion, we used prostate-specific Pten-knockout mice, an immune-competent, orthotopic prostate cancer model, and diets with defined polyunsaturated fatty acid levels. We found that omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival, whereas omega-6 fatty acids had opposite effects. Introducing an omega-3 desaturase, which converts omega-6 to omega-3 fatty acids, into the Pten-knockout mice reduced tumor growth similarly to the omega-3 diet. Tumors from mice on the omega-3 diet had lower proportions of phosphorylated Bad and higher apoptotic indexes compared with those from mice on omega-6 diet. Knockdown of Bad eliminated omega-3–induced cell death, and introduction of exogenous Bad restored the sensitivity to omega-3 fatty acids. Our data suggest that modulation of prostate cancer development by polyunsaturated fatty acids is mediated in part through Bad-dependent apoptosis. This study highlights the importance of gene-diet interactions in prostate cancer. PMID:17607361

  3. Fatty acid profile of beef from immunocastrated (BOPRIVA(®)) Nellore bulls.

    PubMed

    Andreo, Nayara; Bridi, Ana Maria; Soares, Adriana Lourenço; Prohmann, Paulo Emílio Fernandes; Peres, Louise Manha; Tarsitano, Marina Avena; de Lima Giangareli, Barbara; Takabayashi, Alyson Akira

    2016-07-01

    Twenty Nellore bulls (ABW=357.7±9.65kg) were divided into 2 groups: intact and immunocastrated - Bopriva®. After the trial period, the cattle were slaughtered and carcass fat thickness was evaluated, ether extract and fatty acid composition of the longissimus thoracis analyses were performed, and the activity indices of relevant enzymes were calculated. The means were calculated and compared by Student's t-test and Pearson's correlation coefficients (p<0.05). The immunocastrated group showed higher back fat thickness, ether extract, monounsaturated fatty acids (MUFAs), and activity index of Δ(9) desaturase C18 and lower polyunsaturated fatty acids (PUFAs) and n-6 fatty acids when compared to the intact group. The correlations between ether extract and the saturated and monounsaturated fatty acids were positive, and negative with polyunsaturated, n-3, n-6 and PUFA/SFA. Therefore, immunocastration may improve the fatty acid profile in the longissimus thoracis by increasing MUFAs, mainly oleic acid that is the most representative fatty acid in the meat and is considered beneficial to health.

  4. Dietary conjugated linoleic acid modify gene expression in liver, muscles, and fat tissues of finishing pigs.

    PubMed

    Tous, N; Theil, P K; Lauridsen, C; Lizardo, R; Vilà, B; Esteve-Garcia, E

    2012-12-01

    The aim of this study was to investigate underlying mechanisms of dietary conjugated linoleic acid (CLA) on lipid metabolism in various tissues of pigs. Sixteen gilts (73 ± 3 kg) were fed a control (containing sunflower oil) or an experimental diet in which 4% of sunflower oil was replaced by CLA, and slaughtered at an average BW of 117 ± 4.9 kg. Transcription of peroxisome proliferator-activated receptor alpha (PPARα), peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FAS), sterol regulatory element binding protein (SREBP1), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), delta-6-desaturase (D6D), and stearoyl CoA desaturase (SCD) were determined by real-time PCR in longissimus thoracis (LT) and semimembranosus (SM) muscles, LT subcutaneous and SM intermuscular fat, and in the liver. Fatty acid (FA) composition was analyzed using gas chromatography in these tissues, except for SM intermuscular fat. Dietary CLA increased PPARγ in LT muscle (P < 0.05), whereas CLA reduced PPARα transcription in all tissues studied (P < 0.05) with the exception of intermuscular fat. Transcription of genes related to FA synthesis was reduced by CLA in SM muscle and liver (SREBP1, both P < 0.1; ACC, P < 0.01 in SM; and FAS, P < 0.01 in liver), whereas CLA reduced (P < 0.05) LPL and D6D transcriptions in SM muscle and reduced (P < 0.05) SCD in liver but increased (P < 0.05) SCD in LT muscle and intermuscular fat. Saturated FA were increased in all studied tissues (P < 0.01), while monosaturated and polyunsaturated FA were reduced in a tissue-specific way by CLA. It was concluded that dietary CLA affected transcription of genes and fat metabolism in a tissue-specific manner.

  5. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells.

    PubMed

    Aimola, Idowu A; Inuwa, Hajiya M; Nok, Andrew J; Mamman, Aisha I; Bieker, James J

    2016-04-05

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ(9) desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ(9)-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer.

  6. Study of the serum levels of polyunsaturated fatty acids and the expression of related liver metabolic enzymes in a rat valproate-induced autism model.

    PubMed

    Zhao, Gang; Gao, Jingquan; Liang, Shuang; Wang, Xuelai; Sun, Caihong; Xia, Wei; Hao, Yanqiu; Li, Xiang; Cao, Yonggang; Wu, Lijie

    2015-08-01

    To investigate whether the decreased level of serum polyunsaturated fatty acids (PUFAs) in patients with autism is associated with the expression of related liver metabolic enzymes, we selected rats that were exposed to valproic acid (VPA) on embryonic day 12.5 (E12.5) as a model of autism. We observed the serum levels of PUFAs and the expression of related liver metabolic enzymes, including Δ5-desaturase, Δ6-desaturase and elongase (Elovl2), in VPA-exposed and control rats on postnatal day 35 (PND35) and conducted sex dimorphic analysis. We found that the levels of serum PUFAs and related liver metabolic enzymes in the VPA rats were significantly reduced, in association with autism-like behavioral changes, the abnormal expression of apoptosis-related proteins and hippocampal neuronal injury, compared to the control rats and showed sex difference in VPA group. This finding indicated that rats exposed to VPA at the embryonic stage may exhibit reduced synthesis of serum PUFAs due to the down-regulation of liver metabolic enzymes, thereby inducing nervous system injury and behavioral changes, which is affected by sex in the meantime.

  7. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells

    PubMed Central

    Aimola, Idowu A.; Inuwa, Hajiya M.; Nok, Andrew J.; Mamman, Aisha I.; Bieker, James J.

    2017-01-01

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24 h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ9 desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ9-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer PMID:26879870

  8. Genetic and epigenetic transgenerational implications related to omega-3 fatty acids. Part I: maternal FADS2 genotype and DNA methylation correlate with polyunsaturated fatty acid status in toddlers: an exploratory analysis.

    PubMed

    Lupu, Daniel S; Cheatham, Carol L; Corbin, Karen D; Niculescu, Mihai D

    2015-11-01

    Polyunsaturated fatty acid metabolism in toddlers is regulated by a complex network of interacting factors. The contribution of maternal genetic and epigenetic makeup to this milieu is not well understood. In a cohort of mothers and toddlers 16 months of age (n = 65 mother-child pairs), we investigated the association between maternal genetic and epigenetic fatty acid desaturase 2 (FADS2) profiles and toddlers' n-6 and n-3 fatty acid metabolism. FADS2 rs174575 variation and DNA methylation status were interrogated in mothers and toddlers, as well as food intake and plasma fatty acid concentrations in toddlers. A multivariate fit model indicated that maternal rs174575 genotype, combined with DNA methylation, can predict α-linolenic acid plasma concentration in all toddlers and arachidonic acid concentrations in boys. Arachidonic acid intake was predictive for its plasma concentration in girls, whereas intake of 3 major n-3 species (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were predictive for their plasma concentrations in boys. FADS2 genotype and DNA methylation in toddlers were not related to plasma concentrations or food intakes, except for CpG8 methylation. Maternal FADS2 methylation was a predictor for the boys' α-linolenic acid intakes. This exploratory study suggests that maternal FADS2 genetic and epigenetic status could be related to toddlers' polyunsaturated fatty acid metabolism.

  9. Effects of Addition of Linseed and Marine Algae to the Diet on Adipose Tissue Development, Fatty Acid Profile, Lipogenic Gene Expression, and Meat Quality in Lambs

    PubMed Central

    Urrutia, Olaia; Mendizabal, José Antonio; Insausti, Kizkitza; Soret, Beatriz; Purroy, Antonio; Arana, Ana

    2016-01-01

    This study examined the effect of linseed and algae on growth and carcass parameters, adipocyte cellularity, fatty acid profile and meat quality and gene expression in subcutaneous and intramuscular adipose tissues (AT) in lambs. After weaning, 33 lambs were fed three diets up to 26.7 ± 0.3 kg: Control diet (barley and soybean); L diet (barley, soybean and 10% linseed) and L-A diet (barley, soybean, 5% linseed and 3.89% algae). Lambs fed L-A diet showed lower average daily gain and greater slaughter age compared to Control and L (P < 0.001). Carcass traits were not affected by L and L-A diets, but a trend towards greater adipocyte diameter was observed in L and L-A in the subcutaneous AT (P = 0.057). Adding either linseed or linseed and algae increased α-linolenic acid and eicosapentaenoic acid contents in both AT (P < 0.001); however, docosahexaenoic acid was increased by L-A (P < 0.001). The n-6/n-3 ratio decreased in L and L-A (P < 0.001). Algae had adverse effects on meat quality, with greater lipid oxidation and reduced ratings for odor and flavor. The expression of lipogenic genes was downregulated in the subcutaneous AT (P < 0.05): acetyl-CoA carboxylase 1 (ACACA) in L and L-A and lipoprotein lipase (LPL) and stearoyl-CoA desaturase (SCD) in L-A. Fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and fatty acid elongase 5 (ELOVL5) were unaffected. In the subcutaneous AT, supplementing either L or L-A increased peroxisome proliferator-activated receptor gamma (PPARG) and CAAT-enhancer binding protein alpha (CEBPA) (P < 0.05), although it had no effect on sterol regulatory element-binding factor 1 (SREBF1). In the intramuscular AT, expression of ACACA, SCD, FADS1 and FADS2 decreased in L and L-A (P < 0.001) and LPL in L (P < 0.01), but PPARG, CEBPA and SREBF1 were unaffected. PMID:27253325

  10. Five Decades with Polyunsaturated Fatty Acids: Chemical Synthesis, Enzymatic Formation, Lipid Peroxidation and Its Biological Effects

    PubMed Central

    Catalá, Angel

    2013-01-01

    I have been involved in research on polyunsaturated fatty acids since 1964 and this review is intended to cover some of the most important aspects of this work. Polyunsaturated fatty acids have followed me during my whole scientific career and I have published a number of studies concerned with different aspects of them such as chemical synthesis, enzymatic formation, metabolism, transport, physical, chemical, and catalytic properties of a reconstructed desaturase system in liposomes, lipid peroxidation, and their effects. The first project I became involved in was the organic synthesis of [1-14C] eicosa-11,14-dienoic acid, with the aim of demonstrating the participation of that compound as a possible intermediary in the biosynthesis of arachidonic acid “in vivo.” From 1966 to 1982, I was involved in several projects that study the metabolism of polyunsaturated fatty acids. In the eighties, we studied fatty acid binding protein. From 1990 up to now, our laboratory has been interested in the lipid peroxidation of biological membranes from various tissues and different species as well as liposomes prepared with phospholipids rich in PUFAs. We tested the effect of many antioxidants such as alpha tocopherol, vitamin A, melatonin and its structural analogues, and conjugated linoleic acid, among others. PMID:24490074

  11. Paper-based electroanalytical devices for in situ determination of salicylic acid in living tomato leaves.

    PubMed

    Sun, Li-Jun; Feng, Qiu-Mei; Yan, Yong-Feng; Pan, Zhong-Qin; Li, Xiao-Hui; Song, Feng-Ming; Yang, Haibing; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

    2014-10-15

    Detection of phytohormones in situ has gained significant attention due to their critical roles in regulating developmental processes and signaling for defenses in plants at low concentration. As one type of plant hormones, salicylic acid has recently been found to be one of pivotal signal molecules for physiological behaviors of plants. Here we report the application of paper-based electroanalytical devices for sensitively in situ detection of salicylic acid in tomato leaves with the sample volume of several microliters. Specifically, disposable working electrodes were fabricated by coating carbon tape with the mixture of multiwall carbon nanotubes and nafion. We observed that the treatment of the modified carbon tape electrodes with oxygen plasma could significantly improve electrochemical responses of salicylic acid. The tomato leaves had a punched hole of 1.5mm diameter to release salicylic acid with minor influence on continuous growth of tomatoes. By incorporating the tomato leaf with the paper-based analytical device, we were able to perform in situ determination of salicylic acid based on its electrocatalytic oxidation. Our experimental results demonstrated that the amounts of salicylic acid differed statistically in normal, phytoene desaturase (PDS) gene silent and diseased (infected by Botrytis cinerea) tomato leaves. By quantifying salicylic acid at the level of several nanograms in situ, the simple paper-based electroanalytical devices could potentially facilitate the study of defense mechanism of plants under biotic and abiotic stresses. This study might also provide a sensitive method with spatiotemporal resolution for mapping of chemicals released from living organisms.

  12. Kinetic analysis of delta-6-desaturation in liver microsomes: influence of gamma-linoleic acid dietary supplementation to young and old rats.

    PubMed

    Hrelia, S; Bordoni, A; Motta, P; Celadon, M; Biagi, P L

    1991-11-01

    Previous experiments demonstrated the ability-of a gamma-linoleic acid (GLA) dietary supplementation (as evening primrose oil--EPO) to counteract the fall off in delta-6-desaturase (D6D) activity of linoleic acid and alpha-linoleic acid in aged rats. Kinetic parameters of the D6D were determined in order to test the possibility that there may be a significant influence of GLA administration to young and aged rats on the Vm and Km values for 6-desaturation of both the substrates. In young rats GLA supplementation did not affect the kinetic parameters, while in old rats it produced an increase of Vm values of 6-desaturation for both the substrates. Thus the administration of small doses of GLA to old rats might offer substantial protection against the loss of D6D affinity observed in aging, enhancing the capacity of the enzyme itself.

  13. In Vitro Stepwise Reconstitution of Amino Acid Derived Vinyl Isocyanide Biosynthesis: Detection of an Elusive Intermediate.

    PubMed

    Chang, Wei-Chen; Sanyal, Dev; Huang, Jhih-Liang; Ittiamornkul, Kuljira; Zhu, Qin; Liu, Xinyu

    2017-02-17

    In vitro reconstitution of a newly discovered isonitrile synthase (AmbI1 and AmbI2) and the detection of an elusive intermediate (S)-3-(1H-indol-3-yl)-2-isocyanopropanoic acid 1 in indolyl vinyl isocyanide biogenesis are reported. The characterization of iron/2-oxoglutarate (Fe/2OG) dependent desaturases IsnB and AmbI3 sheds light on the possible mechanism underlying stereoselective alkene installation to complete the biosynthesis of (E)- and (Z)-3-(2-isocyanovinyl)-1H-indole 2 and 5. Establishment of a tractable isonitrile synthase system (AmbI1 and AmbI2) paves the way to elucidate the enigmatic enzyme mechanism for isocyanide formation.

  14. Hepatic fatty acid biosynthesis is more responsive to protein than carbohydrate in rainbow trout during acute stimulations.

    PubMed

    Dai, Weiwei; Panserat, Stéphane; Kaushik, Sadasivam; Terrier, Frédéric; Plagnes-Juan, Elisabeth; Seiliez, Iban; Skiba-Cassy, Sandrine

    2016-01-01

    The link between dietary carbohydrate/protein and de novo lipogenesis (DNL) remains debatable in carnivorous fish. We aimed to evaluate and compare the response of hepatic lipogenic gene expression to dietary carbohydrate intake/glucose and dietary protein intake/amino acids (AAs) during acute stimulations using both in vivo and in vitro approaches. For the in vivo trial, three different diets and a controlled-feeding method were employed to supply fixed amount of dietary protein or carbohydrate in a single meal; for the in vitro trial, primary hepatocytes were stimulated with a low or high level of glucose (3 mM or 20 mM) and a low or high level of AAs (one-fold or four-fold concentrated AAs). In vitro data showed that a high level of AAs upregulated the expression of enzymes involved in DNL [fatty acid synthase (FAS) and ATP citrate lyase (ACLY)], lipid bioconversion [elongation of very long chain fatty acids like-5 (Elovl5), Elovl2, Δ6 fatty acyl desaturase (D6D) and stearoyl-CoA desaturase-1 (SCD1)], NADPH production [glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme (ME)], and transcriptional factor sterol regulatory element binding protein 1-like, while a high level of glucose only elevated the expression of ME. Data in trout liver also showed that high dietary protein intake induced higher lipogenic gene expression (FAS, ACLY, and Elovl2) regardless of dietary carbohydrate intake, while high carbohydrate intake markedly suppressed the expression of acetyl-CoA carboxylase (ACC) and Elovl5. Overall, we conclude that, unlike rodents or humans, hepatic fatty acid biosynthetic gene expression in rainbow trout is more responsive to dietary protein intake/AAs than dietary carbohydrate intake/glucose during acute stimulations. This discrepancy probably represents one important physiological and metabolic difference between carnivores and omnivores.

  15. Carcass traits and meat fatty acid composition of Barbarine lambs reared on rangelands or indoors on hay and concentrate.

    PubMed

    Majdoub-Mathlouthi, L; Saïd, B; Kraiem, K

    2015-12-01

    The objective of this study was to compare carcass and meat quality between Barbarine lambs raised on rangelands and those reared indoors. A total of 24 weaned male lambs (23.2 kg) were allotted into two groups. The first group (GS) grazed pasture dominated by natural shrubs and was supplemented with 100 g of concentrate. The second group (HS) received oat hay and 200 to 300 g supplement of the same concentrate in order to obtain the same average daily gain (ADG) as the GS group. Six lambs from each group were slaughtered. Lambs to be slaughtered were randomly identified at the beginning of the trial. Carcass traits (offals percentage, dressing percentage, cuts yield, tissue composition, fatness and conformation) were determined; pH and meat and fat color were measured. Samples from longissimus lumborum were collected to analyze fatty acid composition. The GS group was characterized by a higher offals percentage, associated with higher lungs, heart, liver and kidney percentage. Carcass dressing percentage defined as the rate between hot carcass weight and empty BW was lower by 3.4% in the GS group. No differences were observed for carcass meat yield and carcass and leg compactness. Shoulder bone percentage of the GS group was higher, without differences in fat and lean percentages. Fat thickness, kidney and tail fats were lower in the GS lambs. However, intramuscular fat content was not affected. Percentages of saturated fatty acids and polyunsaturated fatty acids (PUFA) were not modified, whereas levels of n-3 and long n-3PUFA (EPA, DPA and DHA) as well as Δ5 desaturase plus Δ6 desaturase index were higher for the GS group. Thrombogenic and atherogenic indexes were not altered. No significant effects were observed for meat pH, meat and fat color. Despite having the same ADG, lambs from the GS group were less fatty, and their meat was richer in beneficial fatty acids.

  16. Fine mapping of porcine SSC14 QTL and SCD gene effects on fatty acid composition and melting point of fat in a Duroc purebred population.

    PubMed

    Uemoto, Y; Nakano, H; Kikuchi, T; Sato, S; Ishida, M; Shibata, T; Kadowaki, H; Kobayashi, E; Suzuki, K

    2012-04-01

    The stearoyl-CoA desaturase (delta-9-desaturase; SCD) gene is a candidate gene for fatty acid composition. It is located on pig SSC14 in a region where quantitative trait loci (QTL) for fatty acid composition were previously detected in a Duroc purebred population. The objective of the present study was to fine map the QTL, to identify polymorphisms of the pig SCD gene and to examine the effects of SCD polymorphisms on fatty acid composition and melting point of fat in the population. The pigs were examined for fatty acid composition and melting point of inner and outer subcutaneous fat and inter- and intramuscular fat; the number of pigs examined was 479-521. Two SNPs (g.-353C>T and g.-233T>C) were identified in the promoter region of the SCD gene and were completely linked in the pigs from the base generation. In all pigs, 19 microsatellite markers and SCD haplotypes were then genotyped. Different statistical models were applied to evaluate the effects of QTL and the possible causality of the SCD gene variants with respect to the QTL. The results show that all significant QTL for C14:0, C18:0, C18:1 and melting point of fat were detected in the same region, located near the SCD gene. The results also show a significant association between SCD haplotypes and fatty acid composition and fat melting point in this population. These results indicate that the haplotype of the SCD gene has a strong effect on fatty acid composition and melting point of fat.

  17. Effect of feeding lambs with a tanniferous shrub (rockrose) and a vegetable oil blend on fatty acid composition of meat lipids.

    PubMed

    Francisco, A; Alves, S P; Portugal, P V; Pires, V M R; Dentinho, M T; Alfaia, C M; Jerónimo, E; Prates, J A M; Santos-Silva, J; Bessa, R J B

    2016-12-01

    The effects of feeding Cistus ladanifer (Cistus) and a blend of soybean and linseed oil (1 : 2 vol/vol) on fatty acid (FA) composition of lamb meat lipids and messenger RNA (mRNA) expression of desaturase enzymes was assessed. In total, 54 male lambs were randomly assigned to 18 pens and to nine diets, resulting from the combination of three inclusion levels of Cistus (50 v. 100 v. 200 g/kg of dry matter (DM)) and three inclusion levels of oil (0 v. 40 v. 80 g/kg of DM). The forage-to-concentrate ratio of the diets was 1 : 1. Longissimus muscle lipids were extracted, fractionated into neutral (NL) and polar lipid (PL) and FA methyl esters obtained and analyzed by GLC. The expression of genes encoding Δ5, Δ6 and Δ9 desaturases (fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and stearoyl CoA desaturase (SCD)) was determined. Intramuscular fat, NL and PL contents were not affected by oil or Cistus. Oil supplementation reduced (P<0.05) 16:0, c9-16:1, 17:0, c9-17:1 and c9-18:1 FA and increased (P<0.05) 18:2n-6, 18:3n-3 and the majority of biohydrogenation intermediates in NL. Cistus alone had few effects on FA of NL but interacted with oil (P<0.05) by increasing t10-18:1,t10,t12-18:2,t10,c12-18:2 and t7,c9-18:2. The t10-/t11-18:1 ratio increased with both Cistus and oil levels. The c9, t11-18:2 did not increase (P<0.05) with both oil and Cistus dietary inclusion. Oil reduced c9-16:1, 17:0, c9-17:1,c9-18:1, 20:4n-6, 22:4n-6 and 20:3n-9 proportions in PL, and increased 18:2n-6, 18:3n-3, 20:3n-3 and of most of the biohydrogenation intermediates. The Cistus had only minor effects on FA composition of PL. Cistus resulted in a reduction (P<0.05) of 20:5n-3 and 22:6n-3 in the meat PL. The expression level of SCD mRNA increased (P=0.015) with Cistus level, although a linear relationship with condensed tannins intake (P=0.11) could not be established. FADS1 mRNA expressed levels increased linearly (P=0.019) with condensed tannins intake. In summary, the

  18. Responses to oleic, linoleic and α-linolenic acids in high-carbohydrate, high-fat diet-induced metabolic syndrome in rats.

    PubMed

    Poudyal, Hemant; Kumar, Senthil A; Iyer, Aarjit; Waanders, Jennifer; Ward, Leigh C; Brown, Lindsay

    2013-07-01

    We investigated the changes in adiposity, cardiovascular and liver structure and function, and tissue fatty acid compositions in response to oleic acid-rich macadamia oil, linoleic acid-rich safflower oil and α-linolenic acid-rich flaxseed oil (C18 unsaturated fatty acids) in rats fed either a diet high in simple sugars and mainly saturated fats or a diet high in polysaccharides (cornstarch) and low in fat. The fatty acids induced lipid redistribution away from the abdomen, more pronounced with increasing unsaturation; only oleic acid increased whole-body adiposity. Oleic acid decreased plasma total cholesterol without changing triglycerides and nonesterified fatty acids, whereas linoleic and α-linolenic acids decreased plasma triglycerides and nonesterified fatty acids but not cholesterol. α-Linolenic acid improved left ventricular structure and function, diastolic stiffness and systolic blood pressure. Neither oleic nor linoleic acid changed the left ventricular remodeling induced by high-carbohydrate, high-fat diet, but both induced dilation of the left ventricle and functional deterioration in low fat-diet-fed rats. α-Linolenic acid improved glucose tolerance, while oleic and linoleic acids increased basal plasma glucose concentrations. Oleic and α-linolenic acids, but not linoleic acid, normalized systolic blood pressure. Only oleic acid reduced plasma markers of liver damage. The C18 unsaturated fatty acids reduced trans fatty acids in the heart, liver and skeletal muscle with lowered stearoyl-CoA desaturase-1 activity index; linoleic and α-linolenic acids increased accumulation of their C22 elongated products. These results demonstrate different physiological and biochemical responses to primary C18 unsaturated fatty acids in a rat model of human metabolic syndrome.

  19. Conjugated linoleic acid and vaccenic acid in rumen, plasma, and milk of cows fed fish oil and fats differing in saturation of 18 carbon fatty acids.

    PubMed

    AbuGhazaleh, A A; Schingoethe, D J; Hippen, A R; Kalscheur, K F

    2003-11-01

    The objective of this study was to examine the effect of feeding fish oil (FO) along with fat sources that varied in saturation of 18 carbon fatty acids (high stearic, high oleic, high linoleic, or high linolenic acids) on rumen, plasma, and milk fatty acid profiles. Four primiparous Holstein cows at 85 d in milk (+/- 40) were assigned to 4 x 4 Latin squares with 4-wk periods. Treatment diets were 1) 1% FO plus 2% commercial fat high in stearic acid (HS); 2) 1% FO plus 2% fat from high oleic acid sunflower seeds (HO); 3) 1% FO plus 2% fat from high linoleic acid sunflower seeds (HLO); and 4) 1% FO plus 2% fat from flax seeds (high linolenic; HLN). Diets were formulated to contain 18% crude protein and were composed of 50% (dry basis) concentrate mix, 25% corn silage, 12.5% alfalfa silage, and 12.5% alfalfa hay. Milk production, milk protein percentages and yields, and dry matter intake were similar across diets. Milk fat concentrations and yields were least for HO and HLO diets. The proportion of milk cis-9, trans-11 conjugated linoleic acid (CLA; 0.71, 0.99, 1.71, and 1.12 g/100 g fatty acids, respectively), and vaccenic acid (TVA; 1.85, 2.60, 4.14, and 2.16 g/100 g fatty acids, respectively) were greatest with the HLO diet. The proportions of ruminal cis-9, trans-11 CLA (0.09, 0.16, 0.18, and 0.16 g/100 g fatty acids, respectively) were similar for the HO, HLO, and HLN diets and all were higher than for the HS diet. The proportions of TVA (2.85, 4.36, 8.69, and 4.64 g/100 g fatty acids, respectively) increased with the HO, HLO, and HLN diets compared with the HS diets, and the increase was greatest with the HLO diet. The effects of fat supplements on ruminal TVA concentrations were also reflected in plasma triglycerides, (2.75, 4.64, 8.77, and 5.42 g/100 g fatty acids, respectively); however, there were no differences in the proportion of cis-9, trans-11 CLA (0.06, 0.07, 0.06, and 0.07 g/100 g fatty acids, respectively). This study further supports the

  20. Metabolism of Hydroxy Fatty Acids in Developing Seeds in the Genera Lesquerella (Brassicaceae) and Linum (Linaceae).

    PubMed Central

    Reed, D. W.; Taylor, D. C.; Covello, P. S.

    1997-01-01

    Members of the genus Lesquerella produce seed oil that contains a high proportion of hydroxy fatty acids (HFAs). There are three groups of Lesquerella species that are distinguished by their most abundant seed oil fatty acid: lesquerolic acid (20:1OH; e.g. Lesquerella fendleri), densipolic acid (18:2OH; e.g. Lesquerella kathryn), and auricolic acid (20:2OH; e.g. Lesquerella auriculata). To investigate the biochemistry of HFA production in Lesquerella species, the conversion of putative radiolabeled intermediates of HFA biosynthesis, including 18:1, 20:1,18:1OH, 18:2OH, and 20:1OH, was examined in developing embryos of L. fendleri, L.kathryn, and L. auriculata. The results are consistent with (a) 18:1OH formation by hydroxylation of 18:1, (b) elongation and desaturation of 18:1OH to produce 20:1OH and 18:2OH, respectively, and (c) desaturation of 20:1OH to produce 20:2OH. The desaturation of 20:1OH was also found to occur in developing embryos of high, but not low, linolenic acid flax. This suggests that the desaturation is catalyzed by the extraplastidial linoleate desaturase. Confirming this suggestion, it was notable that 18:1OH and 18:2OH were found in low and high linolenic flax (Linum usitatissimum) seeds, respectively, at levels of 0.2 to 1%. PMID:12223689

  1. Sterculic Acid and Its Analogues Are Potent Inhibitors of Toxoplasma gondii

    PubMed Central

    Hao, Pan; Alaraj, Intisar Q. M.; Dulayymi, Juma’a R. Al; Baird, Mark S.; Liu, Jing; Liu, Qun

    2016-01-01

    Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis. PMID:27180571

  2. Genome-Wide Association Study of Genetic Control of Seed Fatty Acid Biosynthesis in Brassica napus

    PubMed Central

    Gacek, Katarzyna; Bayer, Philipp E.; Bartkowiak-Broda, Iwona; Szala, Laurencja; Bocianowski, Jan; Edwards, David; Batley, Jacqueline

    2017-01-01

    Fatty acids and their composition in seeds determine oil value for nutritional or industrial purposes and also affect seed germination as well as seedling establishment. To better understand the genetic basis of seed fatty acid biosynthesis in oilseed rape (Brassica napus L.) we applied a genome-wide association study, using 91,205 single nucleotide polymorphisms (SNPs) characterized across a mapping population with high-resolution skim genotyping by sequencing (SkimGBS). We identified a cluster of loci on chromosome A05 associated with oleic and linoleic seed fatty acids. The delineated genomic region contained orthologs of the Arabidopsis thaliana genes known to play a role in regulation of seed fatty acid biosynthesis such as Fatty acyl-ACP thioesterase B (FATB) and Fatty Acid Desaturase (FAD5). This approach allowed us to identify potential functional genes regulating fatty acid composition in this important oil producing crop and demonstrates that this approach can be used as a powerful tool for dissecting complex traits for B. napus improvement programs. PMID:28163710

  3. Metabolic engineering of seeds can achieve levels of omega-7 fatty acids comparable to the highest levels found in natural plant sources

    SciTech Connect

    Nguyen, H.T.; Shanklin, J.; Mishra, G.; Whittle, E.; Bevan, S. A.; Merlo, A. O.; Walsh, T. A.

    2010-12-01

    Plant oils containing {omega}-7 fatty acids (FAs; palmitoleic 16:1{Delta}{sup 9} and cis-vaccenic 18:1{Delta}{sup 11}) have potential as sustainable feedstocks for producing industrially important octene via metathesis chemistry. Engineering plants to produce seeds that accumulate high levels of any unusual FA has been an elusive goal. We achieved high levels of {omega}-7 FA accumulation by systematic metabolic engineering of Arabidopsis (Arabidopsis thaliana). A plastidial 16:0-ACP desaturase has been engineered to convert 16:0 to 16:1{Delta}{sup 9} with specificity >100-fold than that of naturally occurring paralogs, such as that from cat's claw vine (Doxantha unguis-cati). Expressing this engineered enzyme (Com25) in seeds increased {omega}-7 FA accumulation from <2% to 14%. Reducing competition for 16:0-ACP by down-regulating the {beta}-ketoacyl-ACP synthase II 16:0 elongase further increased accumulation of {omega}-7 FA to 56%. The level of 16:0 exiting the plastid without desaturation also increased to 21%. Coexpression of a pair of fungal 16:0 desaturases in the cytosol reduced the 16:0 level to 11% and increased {omega}-7 FA to as much as 71%, equivalent to levels found in Doxantha seeds.

  4. Metabolic Engineering of Seeds Can Achieve Levels of ω-7 Fatty Acids Comparable with the Highest Levels Found in Natural Plant Sources1[OA

    PubMed Central

    Nguyen, Huu Tam; Mishra, Girish; Whittle, Edward; Pidkowich, Mark S.; Bevan, Scott A.; Merlo, Ann Owens; Walsh, Terence A.; Shanklin, John

    2010-01-01

    Plant oils containing ω-7 fatty acids (FAs; palmitoleic 16:1Δ9 and cis-vaccenic 18:1Δ11) have potential as sustainable feedstocks for producing industrially important octene via metathesis chemistry. Engineering plants to produce seeds that accumulate high levels of any unusual FA has been an elusive goal. We achieved high levels of ω-7 FA accumulation by systematic metabolic engineering of Arabidopsis (Arabidopsis thaliana). A plastidial 16:0-ACP desaturase has been engineered to convert 16:0 to 16:1Δ9 with specificity >100-fold than that of naturally occurring paralogs, such as that from cat's claw vine (Doxantha unguis-cati). Expressing this engineered enzyme (Com25) in seeds increased ω-7 FA accumulation from <2% to 14%. Reducing competition for 16:0-ACP by down-regulating the β-ketoacyl-ACP synthase II 16:0 elongase further increased accumulation of ω-7 FA to 56%. The level of 16:0 exiting the plastid without desaturation also increased to 21%. Coexpression of a pair of fungal 16:0 desaturases in the cytosol reduced the 16:0 level to 11% and increased ω-7 FA to as much as 71%, equivalent to levels found in Doxantha seeds. PMID:20943853

  5. Regulation of the Omega-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes

    PubMed Central

    Ruyter, Bente; Berge, Gerd Marit; Sun, Yajing; Østbye, Tone-Kari Knutsdatter

    2016-01-01

    Limited availability of the n-3 fatty acids EPA and DHA have led to an interest in better understanding of the n-3 biosynthetic pathway and its regulation. The biosynthesis of alpha-linolenic acid to EPA and DHA involves several complex reaction steps including desaturation-, elongation- and peroxisomal beta-oxidation enzymes. The aims of the present experiments were to gain more knowledge on how this biosynthesis is regulated over time by different doses and fatty acid combinations. Hepatocytes isolated from salmon were incubated with various levels and combinations of oleic acid, EPA and DHA. Oleic acid led to a higher expression of the Δ6 fatty acid desaturase (fad) genes Δ6fad_a, Δ6fad_b, Δ6fad_c and the elongase genes elovl2 compared with cells cultured in medium enriched with DHA. Further, the study showed rhythmic variations in expression over time. Levels were reached where a further increase in specific fatty acids given to the cells not stimulated the conversion further. The gene expression of Δ6fad_a_and Δ6fad_b responded similar to fatty acid treatment, suggesting a co-regulation of these genes, whereas Δ5fad and Δ6fad_c showed a different regulation pattern. EPA and DHA induced different gene expression patterns, especially of Δ6fad_a. Addition of radiolabelled alpha-linolenic acid to the hepatocytes confirmed a higher degree of elongation and desaturation in cells treated with oleic acid compared to cells treated with DHA. This study suggests a complex regulation of the conversion process of n-3 fatty acids. Several factors, such as that the various gene copies are differently regulated, the gene expression show rhythmic variations and gene expression only affected to a certain level, determines when you get the maximum conversion of the beneficial n-3 fatty acids. PMID:27973547

  6. Fibrates modify rat hepatic fatty acid chain elongation and desaturation in vitro.

    PubMed

    Sánchez, R M; Viñals, M; Alegret, M; Vázquez, M; Adzet, T; Merlos, M; Laguna, J C

    1993-11-17

    Three fibric acid derivatives, clofibric acid (CFB), bezafibrate (BFB), and gemfibrozil (GFB), mainly used in the treatment of hypertriglyceridaemic or mixed hyperlipidaemic states, have been tested for their ability to modify fatty acid chain elongation and desaturation in vitro. Both endogenous and exogenous (saturated, monounsaturated and polyunsaturated) fatty acid elongations were inhibited by fibrates at concentrations well within the physiological range (IC50 values for GFB were between 0.1 and 0.3 mM). The potency order was GFB > BFB > CFB. Inhibition was not due to an impairment of the activation step from free fatty acids to acyl-CoAs, as palmitoyl-CoA synthetase was only slightly inhibited (IC50 value for GFB = 2.8 mM). Fibrates (GFB) appeared to behave as mixed non-competitive inhibitors with respect to malonyl-CoA when the rate limiting step of elongation, the condensing enzyme, is assayed. Further, delta 6 and delta 5 desaturates were inhibited by the three drugs (GFB > BFB > CFB), although not to the same extent as the elongation system. In contrast, delta 9 desaturase activity was not affected by fibrates.

  7. Arachidonic and docosahexaenoic acids are biosynthesized from their 18-carbon precursors in human infants.

    PubMed Central

    Salem, N; Wegher, B; Mena, P; Uauy, R

    1996-01-01

    It is becoming clear that an adequate level of long-chain highly unsaturated fatty acids in the nervous system is required for optimal function and development; however, the ability of infants to biosynthesize long-chain fatty acids is unknown. This study explores the capacity of human infants to convert 18-carbon essential fatty acids to their elongated and desaturated forms, in vivo. A newly developed gas chromatography/negative chemical ionization/mass spectrometry method employing 2H-labeled essential fatty acids allowed assessment of this in vivo conversion with very high sensitivity and selectivity. Our results demonstrate that human infants have the capacity to convert dietary essential fatty acids administered enterally as 2H-labeled ethyl esters to their longer-chain derivatives, transport them to plasma, and incorporate them into membrane lipids. The in vivo conversion of linoleic acid (18:2n6) to arachidonic acid (20:4n6) is demonstrated in human beings. All elongases/desaturases necessary for the conversion of linolenic acid (18:3n3) to docosahexaenoic acid (22:6n3) are also active in the first week after birth. Although the absolute amounts of n-3 fatty acid metabolites accumulated in plasma are greater than those of the n-6 family, estimates of the endogenous pools of 18:2n6 and 18:3n3 indicate that n-6 fatty acid conversion rates are greater than those of the n-3 family. While these data clearly demonstrate the capability of infants to biosynthesize 22:6n3, a lipid that is required for optimal neural development, the amounts produced in vivo from 18:3n3 may be inadequate to support the 22:6n3 level observed in breast-fed infants. PMID:8552667

  8. Production of free monounsaturated fatty acids by metabolically engineered Escherichia coli

    PubMed Central

    2014-01-01

    Background Monounsaturated fatty acids (MUFAs) are the best components for biodiesel when considering the low temperature fluidity and oxidative stability. However, biodiesel derived from vegetable oils or microbial lipids always consists of significant amounts of polyunsaturated and saturated fatty acids (SFAs) alkyl esters, which hampers its practical applications. Therefore, the fatty acid composition should be modified to increase MUFA contents as well as enhancing oil and lipid production. Results The model microorganism Escherichia coli was engineered to produce free MUFAs. The fatty acyl-ACP thioesterase (AtFatA) and fatty acid desaturase (SSI2) from Arabidopsis thaliana were heterologously expressed in E. coli BL21 star(DE3) to specifically release free unsaturated fatty acids (UFAs) and convert SFAs to UFAs. In addition, the endogenous fadD gene (encoding acyl-CoA synthetase) was disrupted to block fatty acid catabolism while the native acetyl-CoA carboxylase (ACCase) was overexpressed to increase the malonyl coenzyme A (malonyl-CoA) pool and boost fatty acid biosynthesis. The finally engineered strain BL21ΔfadD/pE-AtFatAssi2&pA-acc produced 82.6 mg/L free fatty acids (FFAs) under shake-flask conditions and FFAs yield on glucose reached about 3.3% of the theoretical yield. Two types of MUFAs, palmitoleate (16:1Δ9) and cis-vaccenate (18:1Δ11) made up more than 75% of the FFA profiles. Fed-batch fermentation of this strain further enhanced FFAs production to a titer of 1.27 g/L without affecting fatty acid compositions. Conclusions This study demonstrated the possibility to regulate fatty acid composition by using metabolic engineering approaches. FFAs produced by the recombinant E. coli strain consisted of high-level MUFAs and biodiesel manufactured from these fatty acids would be more suitable for current diesel engines. PMID:24716602

  9. The Crystal Structure of an Integral Membrane Fatty Acid α-Hydroxylase*

    PubMed Central

    Zhu, Guangyu; Koszelak-Rosenblum, Mary; Connelly, Sara M.; Dumont, Mark E.; Malkowski, Michael G.

    2015-01-01

    Neuronal electrical impulse propagation is facilitated by the myelin sheath, a compact membrane surrounding the axon. The myelin sheath is highly enriched in galactosylceramide (GalCer) and its sulfated derivative sulfatide. Over 50% of GalCer and sulfatide in myelin is hydroxylated by the integral membrane enzyme fatty acid 2-hydroxylase (FA2H). GalCer hydroxylation contributes to the compact nature of the myelin membrane, and mutations in FA2H result in debilitating leukodystrophies and spastic paraparesis. We report here the 2.6 Å crystal structure of sphingolipid α-hydroxylase (Scs7p), a yeast homolog of FA2H. The Scs7p core is composed of a helical catalytic cap domain that sits atop four transmembrane helices that anchor the enzyme in the endoplasmic reticulum. The structure contains two zinc atoms coordinated by the side chains of 10 highly conserved histidines within a dimetal center located near the plane of the cytosolic membrane. We used a yeast genetic approach to confirm the important role of the dimetal-binding histidines in catalysis and identified Tyr-322 and Asp-323 as critical determinants involved in the hydroxylase reaction. Examination of the Scs7p structure, coupled with molecular dynamics simulations, allowed for the generation of a model of ceramide binding to Scs7p. Comparison of the Scs7p structure and substrate-binding model to the structure of steroyl-CoA desaturase revealed significant differences in the architecture of the catalytic cap domain and location of the dimetal centers with respect to the membrane. These observations provide insight into the different mechanisms of substrate binding and recognition of substrates by the hydroxylase and desaturase enzymes. PMID:26515067

  10. Microbial oils as food additives: recent approaches for improving microbial oil production and its polyunsaturated fatty acid content.

    PubMed

    Bellou, Stamatia; Triantaphyllidou, Irene-Eva; Aggeli, Dimitra; Elazzazy, Ahmed Mohammed; Baeshen, Mohammed Nabih; Aggelis, George

    2016-02-01

    In this short review, we summarize the latest research in the production of polyunsaturated microbial oils that are of interest in food technology. The current research targets the productivity of oleaginous microorganisms, as well as the biosynthesis of particular polyunsaturated fatty acids (PUFAs). The most important efforts target the efficiency of the oleaginous machinery, via overexpression of key-enzymes involved in lipid biosynthesis, as well as the minimization of lipid degradation, by repressing genes involved in the β-oxidation pathway. The production of specific PUFAs is approached by homologous or heterologous expression of specific desaturases and elongases involved in PUFA biosynthesis in oleaginous microorganisms. New perspectives, such as the production of triacylglycerols of specific structure and the employment of adaptive experimental evolution for creating robust oleaginous strains able to produce PUFAs are also discussed.

  11. Identification of target genes and processes involved in erucic acid accumulation during seed development in the biodiesel feedstock Pennycress (Thlaspi arvense L.).

    PubMed

    Claver, Ana; Rey, Raquel; López, M Victoria; Picorel, Rafael; Alfonso, Miguel

    2017-01-01

    We studied erucic acid accumulation in the biodiesel feedstock Pennycress (Thlaspi arvense L.) as a first step towards the development of a sustainable strategy for biofuel production in the EU territory. To that end, two inbred Pennycress lines of European origin, "NASC" and "French," were cultivated in a controlled chamber and in experimental field plots, and their growth, seed production and seed oil characteristics analyzed. Differences in some agronomical traits like vernalization (winter-French versus spring-NASC), flowering time (delayed in the French line) and seed production (higher in the French line) were detected. Both lines showed a high amount (35-39%) of erucic acid (22:1(Δ13)) in their seed oil. Biochemical characterization of the Pennycress seed oil indicated that TAG was the major reservoir of 22:1(Δ13). Incorporation of 22:1(Δ13) to TAG occurred very early during seed maturation, concomitant with a decrease of desaturase activity. This change in the acyl fluxes towards elongation was controlled by different genes at different levels. TaFAE1 gene, encoding the fatty acid elongase, seemed to be controlled at the transcriptional level with high expression at the early stages of seed development. On the contrary, the TaFAD2 gene that encodes the Δ12 fatty acid desaturase or TaDGAT1 that catalyzes TAG biosynthesis were controlled post-transcriptionally. TaWRI1, the master regulator of seed-oil biosynthesis, showed also high expression at the early stages of seed development. Our data identified genes and processes that might improve the biotechnological manipulation of Pennycress seeds for high-quality biodiesel production.

  12. Effects of fish oil and starch added to a diet containing sunflower-seed oil on dairy goat performance, milk fatty acid composition and in vivo delta9-desaturation of [13C]vaccenic acid.

    PubMed

    Bernard, Laurence; Mouriot, Julien; Rouel, Jacques; Glasser, Frédéric; Capitan, Pierre; Pujos-Guillot, Estelle; Chardigny, Jean-Michel; Chilliard, Yves

    2010-08-01

    The potential benefits on human health have prompted an interest in developing nutritional strategies for specifically increasing rumenic acid (RA) in ruminant milk. The aims of the present study were to (i) compare two dietary treatments with lipid supplements on milk yield and composition, (ii) measure the in vivo delta9-desaturation of vaccenic acid (VA) to RA using 13C-labelled VA and (iii) determine the effect of the dietary treatments on this variable. Treatments were 90 g sunflower-seed oil (SO) per d or 60 g sunflower-seed oil and 30 g fish oil per d plus additional starch (SFO), in a grassland hay-based diet given to eight Alpine goats in a 2 x 2 cross-over design with 21 d experimental periods. Milk yield and composition were similar between treatments. Goats fed SFO had higher milk 6 : 0-16 : 0 concentration, lower milk sigmaC18 concentrations and showed no effect on milk VA and RA, compared with SO. At the end of the experiment, intravenous injection of 1.5 g [13C]VA followed by measurements of milk lipid 13C enrichment showed that in vivo 31.7 and 31.6 % of VA was delta9-desaturated into milk RA in the caprine with the SO and SFO treatments, respectively. The expression of genes encoding for delta9-desaturase (or stearoyl-CoA desaturase; SCD1, SCD5) in mammary tissues and four milk delta9-desaturation ratios were similar between treatments. In conclusion, the present study provides the first estimates of in vivo endogenous synthesis of RA (63-73 % of milk RA) from VA in goats, and shows no difference between the two lipid supplements compared.

  13. Engineering the production of conjugated fatty acids in Arabidopsis thaliana leaves.

    PubMed

    Yurchenko, Olga; Shockey, Jay M; Gidda, Satinder K; Silver, Maxwell I; Chapman, Kent D; Mullen, Robert T; Dyer, John M

    2017-01-13

    The seeds of many nondomesticated plant species synthesize oils containing high amounts of a single unusual fatty acid, many of which have potential usage in industry. Despite the identification of enzymes for unusual oxidized fatty acid synthesis, the production of these fatty acids in engineered seeds remains low and is often hampered by their inefficient exclusion from phospholipids. Recent studies have established the feasibility of increasing triacylglycerol content in plant leaves, which provides a novel approach for increasing energy density of biomass crops. Here, we determined whether the fatty acid composition of leaf oil could be engineered to accumulate unusual fatty acids. Eleostearic acid (ESA) is a conjugated fatty acid produced in seeds of the tung tree (Vernicia fordii) and has both industrial and nutritional end-uses. Arabidopsis thaliana lines with elevated leaf oil were first generated by transforming wild-type, cgi-58 or pxa1 mutants (the latter two of which contain mutations disrupting fatty acid breakdown) with the diacylglycerol acyltransferases (DGAT1 or DGAT2) and/or oleosin genes from tung. High-leaf-oil plant lines were then transformed with tung FADX, which encodes the fatty acid desaturase/conjugase responsible for ESA synthesis. Analysis of lipids in leaves revealed that ESA was efficiently excluded from phospholipids, and co-expression of tung FADX and DGAT2 promoted a synergistic increase in leaf oil content and ESA accumulation. Taken together, these results provide a new approach for increasing leaf oil content that is coupled with accumulation of unusual fatty acids. Implications for production of biofuels, bioproducts, and plant-pest interactions are discussed.

  14. Conjugated fatty acid synthesis: residues 111 and 115 influence product partitioning of Momordica charantia conjugase.

    PubMed

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-05-11

    Conjugated linolenic acids (CLNs), 18:3 Δ(9,11,13), lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ(9,12,15)). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ(9cis,11trans,13cis)) or α-eleostearic acid (18:3 Δ(9cis,11trans,13trans)). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation.

  15. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  16. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  17. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  18. Double transgenesis of humanized fat1 and fat2 genes promotes omega-3 polyunsaturated fatty acids synthesis in a zebrafish model.

    PubMed

    Pang, Shao-Chen; Wang, Hou-Peng; Li, Kuo-Yu; Zhu, Zuo-Yan; Kang, Jing X; Sun, Yong-Hua

    2014-10-01

    Omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential nutrients for human health. However, vertebrates, including humans, have lost the abilities to synthesize EPA and DHA de novo, majorly due to the genetic absence of delta-12 desaturase and omega-3 desaturase genes. Fishes, especially those naturally growing marine fish, are major dietary source of EPA and DHA. Because of the severe decline of marine fishery and the decrease in n-3 LC-PUFA content of farmed fishes, it is highly necessary to develop alternative sources of n-3 LC-PUFA. In the present study, we utilized transgenic technology to generate n-3 LC-PUFA-rich fish by using zebrafish as an animal model. Firstly, fat1 was proved to function efficiently in fish culture cells, which showed an effective conversion of n-6 PUFA to n-3 PUFA with the n-6/n-3 ratio that decreased from 7.7 to 1.1. Secondly, expression of fat1 in transgenic zebrafish increased the 20:5n-3 and 22:6n-3 contents to 1.8- and 2.4-fold, respectively. Third, co-expression of fat2, a fish codon-optimized delta-12 desaturase gene, and fat1 in fish culture cell significantly promoted n-3 PUFA synthesis with the decreased n-6/n-3 ratio from 7.7 to 0.7. Finally, co-expression of fat1 and fat2 in double transgenic zebrafish increased the 20:5n-3 and 22:6n-3 contents to 1.7- and 2.8-fold, respectively. Overall, we generated two types of transgenic zebrafish rich in endogenous n-3 LC-PUFA, fat1 transgenic zebrafish and fat1/fat2 double transgenic zebrafish. Our results demonstrate that application of transgenic technology of humanized fat1 and fat2 in farmed fishes can largely improve the n-3 LC-PUFA production.

  19. Caffeic Acid Expands Anti-Tumor Effect of Metformin in Human Metastatic Cervical Carcinoma HTB-34 Cells: Implications of AMPK Activation and Impairment of Fatty Acids De Novo Biosynthesis

    PubMed Central

    Tyszka-Czochara, Malgorzata; Konieczny, Pawel; Majka, Marcin

    2017-01-01

    The efficacy of cancer treatments is often limited and associated with substantial toxicity. Appropriate combination of drug targeting specific mechanisms may regulate metabolism of tumor cells to reduce cancer cell growth and to improve survival. Therefore, we investigated the effects of anti-diabetic drug Metformin (Met) and a natural compound caffeic acid (trans-3,4-dihydroxycinnamic acid, CA) alone and in combination to treat an aggressive metastatic human cervical HTB-34 (ATCC CRL­1550) cancer cell line. CA at concentration of 100 µM, unlike Met at 10 mM, activated 5'-adenosine monophosphate-activated protein kinase (AMPK). What is more, CA contributed to the fueling of mitochondrial tricarboxylic acids (TCA) cycle with pyruvate by increasing Pyruvate Dehydrogenase Complex (PDH) activity, while Met promoted glucose catabolism to lactate. Met downregulated expression of enzymes of fatty acid de novo synthesis, such as ATP Citrate Lyase (ACLY), Fatty Acid Synthase (FAS), Fatty Acyl-CoA Elongase 6 (ELOVL6), and Stearoyl-CoA Desaturase-1 (SCD1) in cancer cells. In conclusion, CA mediated reprogramming of glucose processing through TCA cycle via oxidative decarboxylation. The increased oxidative stress, as a result of CA treatment, sensitized cancer cells and, acting on cell biosynthesis and bioenergetics, made HTB-34 cells more susceptible to Met and successfully inhibited neoplastic cells. The combination of Metformin and caffeic acid to suppress cervical carcinoma cells by two independent mechanisms may provide a promising approach to cancer treatment. PMID:28230778

  20. Vitamin B-6 restriction impairs fatty acid synthesis in cultured human hepatoma (HepG2) cells

    PubMed Central

    Zhao, Mei; Ralat, Maria A.; da Silva, Vanessa; Garrett, Timothy J.; Melnyk, Stephan; James, S. Jill

    2013-01-01

    Vitamin B-6 deficiency has been reported to alter n-6 and n-3 fatty acid profiles in plasma and tissue lipids; however, the mechanisms underlying such metabolic changes remain unclear. The objective of this study was to determine the effects of vitamin B-6 restriction on fatty acid profiles and fatty acid synthesis in HepG2 cells. Cells were cultured for 6 wk in media with four different vitamin B-6 concentrations (10, 20, 50, and 2,000 nM added pyridoxal, representing deficient, marginal, adequate, and supraphysiological conditions) that induced a range of steady-state cellular concentrations of pyridoxal phosphate. Total cellular lipid content was greatest in the deficient (10 nM pyridoxal) medium. The percentage of arachidonic acid and the ratio of arachidonic acid to linoleic acid in the total lipid fraction were ∼15% lower in vitamin B-6-restricted cells, which suggests that vitamin B-6 restriction affects n-6 fatty acid interconversions. Metabolic flux studies indicated significantly lower fractional synthesis rate of oleic acid and arachidonic acid at 10, 20, and 50 nM pyridoxal, whereas that of eicosapentaenoic acid was lower in the cells cultured in 10 nM pyridoxal. Additionally, relative mRNA expressions of Δ5 and Δ6 desaturases were 40–50% lower in vitamin B-6-restricted cells. Overall, these findings suggest that vitamin B-6 restriction alters unsaturated fatty acid synthesis, particularly n-6 and n-3 polyunsaturated fatty acid synthesis. These results and observations of changes in human plasma fatty acid profiles caused by vitamin B-6 restriction suggest a mechanism by which vitamin B-6 inadequacy influences the cardiovascular risk. PMID:23211517

  1. Exploring the Lean Phenotype of Glutathione-Depleted Mice: Thiol, Amino Acid and Fatty Acid Profiles

    PubMed Central

    Elshorbagy, Amany K.; Jernerén, Fredrik; Scudamore, Cheryl L.; McMurray, Fiona; Cater, Heather; Hough, Tertius; Cox, Roger; Refsum, Helga

    2016-01-01

    Background Although reduced glutathione (rGSH) is decreased in obese mice and humans, block of GSH synthesis by buthionine sulfoximine (BSO) results in a lean, insulin-sensitive phenotype. Data is lacking about the effect of BSO on GSH precursors, cysteine and glutamate. Plasma total cysteine (tCys) is positively associated with stearoyl-coenzyme A desaturase (SCD) activity and adiposity in humans and animal models. Objective To explore the phenotype, amino acid and fatty acid profiles in BSO-treated mice. Design Male C3H/HeH mice aged 11 weeks were fed a high-fat diet with or without BSO in drinking water (30 mmol/L) for 8 weeks. Amino acid and fatty acid changes were assessed, as well as food consumption, energy expenditure, locomotor activity, body composition and liver vacuolation (steatosis). Results Despite higher food intake, BSO decreased particularly fat mass but also lean mass (both P<0.001), and prevented fatty liver vacuolation. Physical activity increased during the dark phase. BSO decreased plasma free fatty acids and enhanced insulin sensitivity. BSO did not alter liver rGSH, but decreased plasma total GSH (tGSH) and rGSH (by ~70%), and liver tGSH (by 82%). Glutamate accumulated in plasma and liver. Urine excretion of cysteine and its precursors was increased by BSO. tCys, rCys and cystine decreased in plasma (by 23–45%, P<0.001 for all), but were maintained in liver, at the expense of decreased taurine. Free and total plasma concentrations of the SCD products, oleic and palmitoleic acids were decreased (by 27–38%, P <0.001 for all). Conclusion Counterintuitively, block of GSH synthesis decreases circulating tCys, raising the question of whether the BSO-induced obesity-resistance is linked to cysteine depletion. Cysteine-supplementation of BSO-treated mice is warranted to dissect the effects of cysteine and GSH depletion on energy metabolism. PMID:27788147

  2. Conjugated linoleic acids influence fatty acid metabolism in ovine ruminal epithelial cells.

    PubMed

    Masur, F; Benesch, F; Pfannkuche, H; Fuhrmann, H; Gäbel, G

    2016-04-01

    Conjugated linoleic acids (CLA), particularly cis-9,trans-11 (c9t11) and trans-10,cis-12 (t10c12), are used as feed additives to adapt to constantly increasing demands on the performance of lactating cows. Under these feeding conditions, the rumen wall, and the rumen epithelial cells (REC) in particular, are directly exposed to high amounts of CLA. This study determined the effect of CLA on the fatty acid (FA) metabolism of REC and expression of genes known to be modulated by FA. Cultured REC were incubated with c9t11, t10c12, and the structurally similar FA linoleic acid (LA), oleic acid (OA), and trans-vaccenic acid (TVA) for 48 h at a concentration of 100 µM. Cellular FA levels were determined by gas chromatography. Messenger RNA expression levels of stearoyl-CoA desaturase (SCD) and monocarboxylate transporter (MCT) 1 and 4 were quantified by reverse transcription-quantitative PCR. Fatty acid evaluation revealed significant effects of CLA, LA, OA, and TVA on the amount of FA metabolites of β-oxidation and elongation and of metabolites related to desaturation by SCD. The observed changes in FA content point (among others) to the ability of REC to synthesize c9t11 from TVA endogenously. The mRNA expression levels of SCD identified a decrease after CLA, LA, OA, or TVA treatment. In line with the changes in mRNA expression, we found reduced amounts of C16:1n-7 cis-9 and C18:1n-9 cis-9, the main products of SCD. The expression of MCT1 mRNA increased after c9t11 and t10c12 treatment, and CLA c9t11 induced an upregulation of MCT4. Application of peroxisome proliferator-activated receptor (PPAR) α antagonist suggested that activation of PPARα is involved in the changes of MCT1, MCT4, and SCD mRNA expression induced by c9t11. Participation of PPARγ in the changes of MCT1 and SCD mRNA expression was shown by the application of the respective antagonist. The study demonstrates that exposure to CLA affects both FA metabolism and regulatory pathways within REC.

  3. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  4. Altered plasma and erythrocyte phospholipid fatty acid profile in elite female water polo and football players.

    PubMed

    Arsić, Aleksandra; Vučić, Vesna; Tepšić, Jasna; Mazić, Sanja; Djelić, Marina; Glibetić, Marija

    2012-02-01

    The impact of chronic, intense exercise, such as in elite athletes, on phospholipids fatty acids (FA) composition has not been studied in women so far. This study aimed to investigate FA profiles in plasma and erythrocytes phospholipids in elite female water polo (N = 15) and football (N = 19) players in comparison with sedentary women. In spite of similar dietary patterns, as assessed by a food frequency questionnaire, plasma FA profile in the football players showed significantly higher proportions of stearic acid, oleic acid, and monounsaturated FA (MUFA), and significantly lower proportions of total and n-6 polyunsaturated FA (PUFA) than in the water polo and control group. The water polo players had higher percentages of palmitoleic acid and arachidonic acid than the control subjects. Erythrocyte FA profile differed among groups. We found significantly higher proportion of oleic acid and MUFA in the football group than in the controls, and decreased stearic acid and elevated palmitic and palmitoleic acid in the water polo players than in the other 2 groups. Both groups of athletes had significantly lower percentages of n-6 dihomo-γ-linolenic acid, n-6 PUFA, and total PUFA compared with the controls. The estimated activities of elongase and desaturases in erythrocytes were also altered in the athletes. Our results indicate that long-term, intense physical training significantly affects FA status of plasma and erythrocyte phospholipids in women. The observed differences between the water polo and the football players suggest that the type of regular training may contribute to the altered metabolism of FA, although possible genetic differences among the 3 study groups cannot be ruled out.

  5. Fatty acid and transcriptome profiling of longissimus dorsi muscles between pig breeds differing in meat quality.

    PubMed

    Yu, Kaifan; Shu, Gang; Yuan, Fangfang; Zhu, Xiaotong; Gao, Ping; Wang, Songbo; Wang, Lina; Xi, Qianyun; Zhang, Shouquan; Zhang, Yongliang; Li, Yan; Wu, Tongshan; Yuan, Li; Jiang, Qingyan

    2013-01-01

    Fat and lean pig breeds show obvious differences in meat quality characteristics including the fatty acid composition of muscle. However, the molecular mechanism underlying these phenotypes differences remains unknown. This study compared meat quality traits between Lantang (a Chinese indigenous breed) and Landrace (a typical lean breed). The Lantang pigs showed higher L* values and intramuscular fat content, lower pH(45min), pH(24h) and shear force in longissimus dorsi (LD) muscle than Landrace (P < 0.05). Fatty acid analysis demonstrated the lower monounsaturated fatty acids (MUFA) and higher polyunsaturated fatty acids (PUFA) percentage in Lantang LD than that in Landrace LD (P < 0.05). To further identify candidate genes for fatty acid composition, the transcriptome of LD muscle from the two breeds were measured by microarrays. There were 586 transcripts differentially expressed, of which 267 transcripts were highly expressed in Lantang pigs. After the validation by real-time quantitative PCR, 13 genes were determined as candidate genes for fatty acid composition of muscle, including Stearoyl-CoA desaturase (SCD). Then, a SCD over-expression plasmid was transfected into C2C12 cells to reveal the effect of SCD on the fatty acid composition in vitro. The results showed that SCD over-expression significantly increased PUFA proportion, while reduced that of saturated fatty acids (SFA) in C2C12 cells (P < 0.05). In summary, this study compared the differences of fatty acid composition and transcriptome in two breeds differing in meat quality, and further identified the novel role of SCD in the regulation of PUFA deposition.

  6. Single Nucleotide Polymorphisms in the FADS Gene Cluster but not the ELOVL2 Gene are Associated with Serum Polyunsaturated Fatty Acid Composition and Development of Allergy (in a Swedish Birth Cohort)

    PubMed Central

    Barman, Malin; Nilsson, Staffan; Torinsson Naluai, Åsa; Sandin, Anna; Wold, Agnes E.; Sandberg, Ann-Sofie

    2015-01-01

    Exposure to polyunsaturated fatty acids (PUFA) influences immune function and may affect the risk of allergy development. Long chain PUFAs are produced from dietary precursors catalyzed by desaturases and elongases encoded by FADS and ELOVL genes. In 211 subjects, we investigated whether polymorphisms in the FADS gene cluster and the ELOVL2 gene were associated with allergy or PUFA composition in serum phospholipids in a Swedish birth-cohort sampled at birth and at 13 years of age; allergy was diagnosed at 13 years of age. Minor allele carriers of rs102275 and rs174448 (FADS gene cluster) had decreased proportions of 20:4 n-6 in cord and adolescent serum and increased proportions of 20:3 n-6 in cord serum as well as a nominally reduced risk of developing atopic eczema, but not respiratory allergy, at 13 years of age. Minor allele carriers of rs17606561 in the ELOVL2 gene had nominally decreased proportions of 20:4 n-6 in cord serum but ELOVL polymorphisms (rs2236212 and rs17606561) were not associated with allergy development. Thus, reduced capacity to desaturase n-6 PUFAs due to FADS polymorphisms was nominally associated with reduced risk for eczema development, which could indicate a pathogenic role for long-chain PUFAs in allergy development. PMID:26633493

  7. Single Nucleotide Polymorphisms in the FADS Gene Cluster but not the ELOVL2 Gene are Associated with Serum Polyunsaturated Fatty Acid Composition and Development of Allergy (in a Swedish Birth Cohort).

    PubMed

    Barman, Malin; Nilsson, Staffan; Torinsson Naluai, Åsa; Sandin, Anna; Wold, Agnes E; Sandberg, Ann-Sofie

    2015-12-03

    Exposure to polyunsaturated fatty acids (PUFA) influences immune function and may affect the risk of allergy development. Long chain PUFAs are produced from dietary precursors catalyzed by desaturases and elongases encoded by FADS and ELOVL genes. In 211 subjects, we investigated whether polymorphisms in the FADS gene cluster and the ELOVL2 gene were associated with allergy or PUFA composition in serum phospholipids in a Swedish birth-cohort sampled at birth and at 13 years of age; allergy was diagnosed at 13 years of age. Minor allele carriers of rs102275 and rs174448 (FADS gene cluster) had decreased proportions of 20:4 n-6 in cord and adolescent serum and increased proportions of 20:3 n-6 in cord serum as well as a nominally reduced risk of developing atopic eczema, but not respiratory allergy, at 13 years of age. Minor allele carriers of rs17606561 in the ELOVL2 gene had nominally decreased proportions of 20:4 n-6 in cord serum but ELOVL polymorphisms (rs2236212 and rs17606561) were not associated with allergy development. Thus, reduced capacity to desaturase n-6 PUFAs due to FADS polymorphisms was nominally associated with reduced risk for eczema development, which could indicate a pathogenic role for long-chain PUFAs in allergy development.

  8. Microbiota-Dependent Hepatic Lipogenesis Mediated by Stearoyl CoA Desaturase 1 (SCD1) Promotes Metabolic Syndrome in TLR5-Deficient Mice.

    PubMed

    Singh, Vishal; Chassaing, Benoit; Zhang, Limin; San Yeoh, Beng; Xiao, Xia; Kumar, Manish; Baker, Mark T; Cai, Jingwei; Walker, Rachel; Borkowski, Kamil; Harvatine, Kevin J; Singh, Nagendra; Shearer, Gregory C; Ntambi, James M; Joe, Bina; Patterson, Andrew D; Gewirtz, Andrew T; Vijay-Kumar, Matam

    2015-12-01

    The gut microbiota plays a key role in host metabolism. Toll-like receptor 5 (TLR5), a flagellin receptor, is required for gut microbiota homeostasis. Accordingly, TLR5-deficient (T5KO) mice are prone to develop microbiota-dependent metabolic syndrome. Here we observed that T5KO mice display elevated neutral lipids with a compositional increase of oleate [C18:1 (n9)] relative to wild-type littermates. Increased oleate contribution to hepatic lipids and liver SCD1 expression were both microbiota dependent. Analysis of short-chain fatty acids (SCFAs) and (13)C-acetate label incorporation revealed elevated SCFA in ceca and hepatic portal blood and increased liver de novo lipogenesis in T5KO mice. Dietary SCFAs further aggravated metabolic syndrome in T5KO mice. Deletion of hepatic SCD1 not only prevented hepatic neutral lipid oleate enrichment but also ameliorated metabolic syndrome in T5KO mice. Collectively, these results underscore the key role of the gut microbiota-liver axis in the pathogenesis of metabolic diseases.

  9. Coexisting role of fasting or feeding and dietary lipids in the control of gene expression of enzymes involved in the synthesis of saturated, monounsaturated and polyunsaturated fatty acids.

    PubMed

    Rodríguez-Cruz, Maricela; Sánchez González, Raúl; Sánchez García, Apolos M; Lòpez-Alarcòn, Mardia

    2012-03-15

    In the liver, maintaining lipid homeostasis is regulated by physiological and exogenous factors. These lipids are synthesized by Fasn, elongases and desaturases. Interactions in an organism among these factors are quite complex and, to date, relatively little is known about them. The aim of this study was to evaluate the coexisting role of physiological (insulin, fasting and feeding) and exogenous (dietary lipids) factors in the control of gene expression of Fasn, elongases and desaturases via Srebf-1c in liver from rats. Gene expression of encoding enzymes for fatty acid synthesis and fatty acid composition was evaluated in liver from rats in fasting and feeding (at 30, 60, 90 and 120 min after feeding) when food intake (adequate or high-lipid diet) was synchronized to a restricted period of 7h. Fasn, Scd and Fads2 were induced during 120 min after initial feeding in both dietary groups. This induction may be activated in part by insulin via Srebf-1c. Also, we showed for the first time that Elovl7 may be regulated by insulin and dietary lipids. The failure to synthesize saturated and monounsaturated fatty acids is consistent with a downregulation of Fasn and Scd, respectively, by dietary lipids. A higher content of LC-PUFAs was observed due to a high expression of Elovl2 and Elovl5, although Fads2 was suppressed by dietary lipids. Therefore, elongases may have a mechanism that is Srebf-1c-independent. This study suggests that a high-lipid diet triggers, during 120 min after initial feeding, a tight coordination among de novo lipogenesis, elongation, and desaturation and may not always be regulated by Srebf-1c. Finally, upregulation by feeding (insulin) of Fasn, Scd, Fads2 and Srebf-1c is insufficient to compensate for the inhibitory effect of dietary lipids.

  10. Development of a nuclear transformation system for Oleaginous Green Alga Lobosphaera (Parietochloris) incisa and genetic complementation of a mutant strain, deficient in arachidonic acid biosynthesis.

    PubMed

    Zorin, Boris; Grundman, Omer; Khozin-Goldberg, Inna; Leu, Stefan; Shapira, Michal; Kaye, Yuval; Tourasse, Nicolas; Vallon, Olivier; Boussiba, Sammy

    2014-01-01

    Microalgae are considered a promising source for various high value products, such as carotenoids, ω-3 and ω-6 polyunsaturated fatty acids (PUFA). The unicellular green alga Lobosphaera (Parietochloris) incisa is an outstanding candidate for the efficient phototrophic production of arachidonic acid (AA), an essential ω-6 PUFA for infant brain development and a widely used ingredient in the baby formula industry. Although phototrophic production of such algal products has not yet been established, estimated costs are considered to be 2-5 times higher than competing heterotrophic production costs. This alga accumulates unprecedented amounts of AA within triacylglycerols and the molecular pathway of AA biosynthesis in L. incisa has been previously elucidated. Thus, progress in transformation and metabolic engineering of this high value alga could be exploited for increasing the efficient production of AA at competitive prices. We describe here the first successful transformation of L. incisa using the ble gene as a selection marker, under the control of the endogenous RBCS promoter. Furthermore, we have succeeded in the functional complementation of the L. incisa mutant strain P127, containing a mutated, inactive version of the delta-5 (Δ5) fatty acid desaturase gene. A copy of the functional Δ5 desaturase gene, linked to the ble selection marker, was transformed into the P127 mutant. The resulting transformants selected for zeocine resistant, had AA biosynthesis partially restored, indicating the functional complementation of the mutant strain with the wild-type gene. The results of this study present a platform for the successful genetic engineering of L. incisa and its long-chain PUFA metabolism.

  11. Fatty acid composition of chicken breast meat is dependent on genotype-related variation of FADS1 and FADS2 gene expression and desaturating activity.

    PubMed

    Boschetti, E; Bordoni, A; Meluzzi, A; Castellini, C; Dal Bosco, A; Sirri, F

    2016-04-01

    In Western countries the dietary guidance emphasizes the need to decrease the intake of saturated fatty acids and to replace them with polyunsaturated fatty acids (PUFA), particularly long chain n-3 PUFA (LC-PUFA). The production of poultry meat having a lower fat content and healthier fatty acid (FA) profile is a hot topic for the poultry industry, and the possibility to identify genotypes able to produce meat with a higher LC-PUFA content deserves attention. The aims of the present study were to evidence in chicken (i) a genotype-related different expression of the desaturating enzymes delta-6 (Δ6, EC 1.14.99.25), delta-5 (Δ5, EC 1.14.19.) and delta-9 (Δ9, EC 1.14.19.1); (ii) the impact of the hypothesized different expression on the meat FA composition; (iii) the distribution of desaturase products in the different lipid classes. Slow (SG), medium (MG) and fast (FG) growing chickens fed the same diet were evaluated either for the relative expression of FADS1, FADS2 and SCD1 genes in liver (by q-PCR), or for the FA composition of breast meat. MG and particularly SG birds showed a greater expression of FADS2 and FADS1 genes, a higher Δ6 and Δ5 activity (estimated using desaturase indices), and consequently a higher LC-PUFA content in the breast meat than FG birds. The relationship between genotype and desaturating ability was demonstrated, with a significant impact on the PUFA content of breast meat. Due to the high consumption rate of avian meat, the identification of the best genotypes for meat production could represent an important goal not only for the food industry, but also for the improvement of human nutrition.

  12. Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

    PubMed

    Martínez, Laura; Torres, Sandra; Baulies, Anna; Alarcón-Vila, Cristina; Elena, Montserrat; Fabriàs, Gemma; Casas, Josefina; Caballeria, Joan; Fernandez-Checa, Jose C; García-Ruiz, Carmen

    2015-12-08

    Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy.

  13. Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis

    PubMed Central

    Martínez, Laura; Torres, Sandra; Baulies, Anna; Alarcón-Vila, Cristina; Elena, Montserrat; Fabriàs, Gemma; Casas, Josefina; Caballeria, Joan; Fernandez-Checa, Jose C.; García-Ruiz, Carmen

    2015-01-01

    Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy. PMID:26539645

  14. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  15. Associations between variants of FADS genes and omega-3 and omega-6 milk fatty acids of Canadian Holstein cows

    PubMed Central

    2014-01-01

    Background Fatty acid desaturase 1 (FADS1) and 2 (FADS2) genes code respectively for the enzymes delta-5 and delta-6 desaturases which are rate limiting enzymes in the synthesis of polyunsaturated omega-3 and omega-6 fatty acids (FAs). Omega-3 and-6 FAs as well as conjugated linoleic acid (CLA) are present in bovine milk and have demonstrated positive health effects in humans. Studies in humans have shown significant relationships between genetic variants in FADS1 and 2 genes with plasma and tissue concentrations of omega-3 and-6 FAs. The aim of this study was to evaluate the extent of sequence variations within these two genes in Canadian Holstein cows as well as the association between sequence variants and health promoting FAs in milk. Results Thirty three SNPs were detected within the studied regions of genes including a synonymous mutation (FADS1-07, rs42187261, 306Tyr > Tyr) in exon 8 of FADS1, a non-synonymous mutation (FADS2-14, rs211580559, 294Ala > Val) within FADS2 exon 7, a splice site SNP (FADS2-05, rs211263660), a 3′UTR SNP (FADS2-23, rs109772589), and another 3′UTR SNP with an effect on a microRNA binding site within FADS2 gene (FADS2-19, rs210169303). Association analyses showed significant relations between three out of seven tested SNPs and several FAs. Significant associations (FDR P < 0.05) were recorded between FADS2-23 (rs109772589) and two omega-6 FAs (dihomogamma linolenic acid [C20:3n6] and arachidonic acid [C20:4n6]), FADS1-07 (rs42187261) and one omega-3 FA (eicosapentaenoic acid, C20:5n3) and tricosanoic acid (C23:0), and one intronic SNP, FADS1-01 (rs136261927) and C20:3n6. Conclusion Our study has demonstrated positive associations between three SNPs within FADS1 and FADS2 genes (a SNP within the 3’UTR, a synonymous SNP and an intronic SNP), with three milk PUFAs of Canadian Holstein cows thus suggesting possible involvement of synonymous and non-coding region variants in FA synthesis. These SNPs may serve as

  16. Stereospecificity of an enzymatic monoene 1,4-dehydrogenation reaction: conversion of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid.

    PubMed

    Rodríguez, Sergio; Clapés, Pere; Camps, Francisco; Fabriàs, Gemma

    2002-04-05

    In this article, we report the first stereochemical study of an enzymatic 1,4-dehydrogenation reaction, namely, the transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid, involved in the sex pheromone biosynthesis of the moth Spodoptera littoralis. The investigation was carried out using the labeled substrates (R)-[10-(2)H]- and (S)-[10-(2)H]-tridecanoic acids ((R)-2 and (S)-2, respectively) and (R)-[2,2,3,3,13-(2)H(5)]- and (S)-[2,2,3,3,13-(2)H(5)]-tetradecanoic acids ((R)-1 and (S)-1, respectively). Probes (R)-2 and (S)-2 were prepared as described in a previous article.(1) The synthesis of the pentadeuterated chiral substrates (R)-1 and (S)-1 was accomplished by kinetic resolution of the racemic 12-tridecyn-2-ol (6) with immobilized porcine pancreatic lipase. The enantiomerically pure alcohols (R)-6 and (S)-6 were transformed into the final acids (S)-1 and (R)-1, respectively, by a sequence of well-established reactions. The analyses of methanolyzed lipidic extracts from glands incubated separatedly with each individual probe showed that in the transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid, both pro-(R) hydrogen atoms at C-10 and C-13 are removed from the substrate. This is the first example reported of a desaturase with pro-(R)/pro-(R) stereospecificities that gives rise to (E)-double bonds. A mechanistic explanation for the stereochemical outcome of this reaction is advanced.

  17. Plant sterol metabolism. Δ(7)-Sterol-C5-desaturase (STE1/DWARF7), Δ(5,7)-sterol-Δ(7)-reductase (DWARF5) and Δ(24)-sterol-Δ(24)-reductase (DIMINUTO/DWARF1) show multiple subcellular localizations in Arabidopsis thaliana (Heynh) L.

    PubMed

    Silvestro, Daniele; Andersen, Tonni Grube; Schaller, Hubert; Jensen, Poul Erik

    2013-01-01

    Sterols are crucial lipid components that regulate membrane permeability and fluidity and are the precursors of bioactive steroids. The plant sterols exist as three major forms, free sterols, steryl glycosides and steryl esters. The storage of steryl esters in lipid droplets has been shown to contribute to cellular sterol homeostasis. To further document cellular aspects of sterol biosynthesis in plants, we addressed the question of the subcellular localization of the enzymes implicated in the final steps of the post-squalene biosynthetic pathway. In order to create a clear localization map of steroidogenic enzymes in cells, the coding regions of Δ(7)-sterol-C(5)-desaturase (STE1/DWARF7), Δ(24)-sterol-Δ(24)-reductase (DIMINUTO/DWARF1) and Δ(5,7)-sterol-Δ(7)-reductase (DWARF5) were fused to the yellow fluorescent protein (YFP) and transformed into Arabidopsis thaliana mutant lines deficient in the corresponding enzymes. All fusion proteins were found to localize in the endoplasmic reticulum in functionally complemented plants. The results show that both Δ(5,7)-sterol-Δ(7)-reductase and Δ(24)-sterol-Δ(24)-reductase are in addition localized to the plasma membrane, whereas Δ(7)-sterol-C(5)-desaturase was clearly detected in lipid particles. These findings raise new challenging questions about the spatial and dynamic cellular organization of sterol biosynthesis in plants.

  18. Mining the bitter melon (momordica charantia l.) seed transcriptome by 454 analysis of non-normalized and normalized cDNA populations for conjugated fatty acid metabolism-related genes

    PubMed Central

    2010-01-01

    Background Seeds of Momordica charantia (bitter melon) produce high levels of eleostearic acid, an unusual conjugated fatty acid with industrial value. Deep sequencing of non-normalized and normalized cDNAs from developing bitter melon seeds was conducted to uncover key genes required for biotechnological transfer of conjugated fatty acid production to existing oilseed crops. It is expected that these studies will also provide basic information regarding the metabolism of other high-value novel fatty acids. Results Deep sequencing using 454 technology with non-normalized and normalized cDNA libraries prepared from bitter melon seeds at 18 DAP resulted in the identification of transcripts for the vast majority of known genes involved in fatty acid and triacylglycerol biosynthesis. The non-normalized library provided a transcriptome profile of the early stage in seed development that highlighted the abundance of transcripts for genes encoding seed storage proteins as well as for a number of genes for lipid metabolism-associated polypeptides, including Δ12 oleic acid desaturases and fatty acid conjugases, class 3 lipases, acyl-carrier protein, and acyl-CoA binding protein. Normalization of cDNA by use of a duplex-specific nuclease method not only increased the overall discovery of genes from developing bitter melon seeds, but also resulted in the identification of 345 contigs with homology to 189 known lipid genes in Arabidopsis. These included candidate genes for eleostearic acid metabolism such as diacylglycerol acyltransferase 1 and 2, and a phospholipid:diacylglycerol acyltransferase 1-related enzyme. Transcripts were also identified for a novel FAD2 gene encoding a functional Δ12 oleic acid desaturase with potential implications for eleostearic acid biosynthesis. Conclusions 454 deep sequencing, particularly with normalized cDNA populations, was an effective method for mining of genes associated with eleostearic acid metabolism in developing bitter melon seeds

  19. RNAi targeting putative genes in phosphatidylcholine turnover results in significant change in fatty acid composition in Crambe abyssinica seed oil.

    PubMed

    Guan, Rui; Li, Xueyuan; Hofvander, Per; Zhou, Xue-Rong; Wang, Danni; Stymne, Sten; Zhu, Li-Hua

    2015-04-01

    The aim of this study was to evaluate the importance of three enzymes, LPCAT, PDCT and PDAT, involved in acyl turnover in phosphatidylcholine in order to explore the possibility of further increasing erucic acid (22:1) content in Crambe seed oil. The complete coding sequences of LPCAT1-1 and LPCAT1-2 encoding lysophosphatidylcholine acyltransferase (LPCAT), PDCT1 and PDCT2 encoding phosphatidylcholine:diacylglycerol cholinephosphotransferase (PDCT), and PDAT encoding phospholipid:diacylglycerol acyltransferase (PDAT) were cloned from developing Crambe seeds. The alignment of deduced amino acid sequences displayed a high similarity to the Arabidopsis homologs. Transgenic lines expressing RNA interference (RNAi) targeting either single or double genes showed significant changes in the fatty acid composition of seed oil. An increase in oleic acid (18:1) was observed, to varying degrees, in all of the transgenic lines, and a cumulative effect of increased 18:1 was shown in the LPCAT-PDCT double-gene RNAi. However, LPCAT single-gene RNAi led to a decrease in 22:1 accumulation, while PDCT or PDAT single-gene RNAi had no obvious effect on the level of 22:1. In agreement with the abovementioned oil phenotypes, the transcript levels of the target genes in these transgenic lines were generally reduced compared to wild-type levels. In this paper, we discuss the potential to further increase the 22:1 content in Crambe seed oil through downregulation of these genes in combination with fatty acid elongase and desaturases.

  20. Effects of dietary alpha- and gamma-linolenic acid on lipid metabolism in young and adult rats.

    PubMed

    Choi, Y S; Sugano, M

    1988-01-01

    The effect of age on lipid metabolism was studied in rats fed diets containing safflower oil (SFO, 78% linoleic acid), evening primrose oil (EPO, 9.4% gamma-linolenic acid and 70% linoleic acid) or the mixture of safflower and linseed oil (SLO, 10.2% alpha-linolenic acid and 68% linoleic acid). The activity of hepatic HMG-CoA reductase declined with age in all groups. In adult rats, the reductase activity was high in the EPO group and low in the SLO group. The activity of hepatic cholesterol 7 alpha-hydroxylase was independent of the diet or age. Hepatic delta 6-desaturase activity was low in adult rats fed EPO. In liver microsomal phospholipids, the percentage of 22:5 n-6 decreased while that of 22:6 n-3 increased with age. The ratio of linoleate metabolites to linoleate was high in the EPO group and low in the SLO group. Liver and serum cholesterol increased with age only in rats fed the SLO diet. Thus, the results indicated an enhanced susceptibility to dietary fats with age.

  1. Fatty Acid Desaturation Links Germ Cell Loss to Longevity Through NHR-80/HNF4 in C. elegans

    PubMed Central

    Goudeau, Jérôme; Bellemin, Stéphanie; Toselli-Mollereau, Esther; Shamalnasab, Mehrnaz; Chen, Yiqun; Aguilaniu, Hugo

    2011-01-01

    Background Preventing germline stem cell proliferation extends lifespan in nematodes and flies. So far, studies on germline-longevity signaling have focused on daf-16/FOXO and daf-12/VDR. Here, we report on NHR-80/HNF4, a nuclear receptor that specifically mediates longevity induced by depletion of the germ line through a mechanism that implicates fatty acid monodesaturation. Methods and Findings nhr-80/HNF4 is induced in animals lacking a germ line and is specifically required for their extended longevity. Overexpressing nhr-80/HNF4 increases the lifespan of germline-less animals. This lifespan extension can occur in the absence of daf-16/FOXO but requires the presence of the nuclear receptor DAF-12/VDR. We show that the fatty acid desaturase, FAT-6/SCD1, is a key target of NHR-80/HNF4 and promotes germline-longevity by desaturating stearic acid to oleic acid (OA). We find that NHR-80/HNF4 and OA must work in concert to promote longevity. Conclusions Taken together, our data indicate that the NHR-80 pathway participates in the mechanism of longevity extension through depletion of the germ line. We identify fat-6 and OA as essential downstream elements although other targets must also be present. Thus, NHR-80 links fatty acid desaturation to lifespan extension through germline ablation in a daf-16/FOXO independent manner. PMID:21423649

  2. FadD Is Required for Utilization of Endogenous Fatty Acids Released from Membrane Lipids ▿ †

    PubMed Central

    Pech-Canul, Ángel; Nogales, Joaquina; Miranda-Molina, Alfonso; Álvarez, Laura; Geiger, Otto; Soto, María José; López-Lara, Isabel M.

    2011-01-01

    FadD is an acyl coenzyme A (CoA) synthetase responsible for the activation of exogenous long-chain fatty acids (LCFA) into acyl-CoAs. Mutation of fadD in the symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti promotes swarming motility and leads to defects in nodulation of alfalfa plants. In this study, we found that S. meliloti fadD mutants accumulated a mixture of free fatty acids during the stationary phase of growth. The composition of the free fatty acid pool and the results obtained after specific labeling of esterified fatty acids with a Δ5-desaturase (Δ5-Des) were in agreement with membrane phospholipids being the origin of the released fatty acids. Escherichia coli fadD mutants also accumulated free fatty acids released from membrane lipids in the stationary phase. This phenomenon did not occur in a mutant of E. coli with a deficient FadL fatty acid transporter, suggesting that the accumulation of fatty acids in fadD mutants occurs inside the cell. Our results indicate that, besides the activation of exogenous LCFA, in bacteria FadD plays a major role in the activation of endogenous fatty acids released from membrane lipids. Furthermore, expression analysis performed with S. meliloti revealed that a functional FadD is required for the upregulation of genes involved in fatty acid degradation and suggested that in the wild-type strain, the fatty acids released from membrane lipids are degraded by β-oxidation in the stationary phase of growth. PMID:21926226

  3. The effect of chemical hepatocarcinogenesis on liver phospholipid composition in rats fed N-6 and N-3 fatty acid-supplemented diets.

    PubMed

    Nassar, B A; Das, U N; Huang, Y S; Ells, G; Horrobin, D F

    1992-03-01

    The effect of dietary fats on essential fatty acid metabolism in rats subjected to chemically induced hepatocarcinogenesis was studied. Sixty male rats were fed a diet supplemented with one of the following three oil compositions: 10% hydrogenated coconut oil (HCO); 5% hydrogenated coconut oil and 5% gamma-linolenic acid (18:3n-6)-rich evening primrose oil (EPO); or 5% hydrogenated coconut oil and 5% marine oil (FO). Half of the animals in each dietary regimen were subjected to hepatocarcinogenesis induction using diethylnitrosamine and 2-acetylaminofluorene (2-AAF) followed by partial hepatectomy, whereas the other half underwent hepatectomy without receiving diethylnitrosamine and 2-acetylaminofluorene. Liver phospholipid composition was analyzed. In comparison to the HCO group, the EPO group showed raised levels of arachidonic acid (20:4n-6) and suppressed n-3 fatty acids. The FO group, on the other hand, showed suppressed levels of n-6 and increased n-3 fatty acids. Hepatocarcinogenesis suppressed the level of 20:4n-6 and this effect was greater in the FO rats. The levels of dihomo-gamma-linolenic acid (20:3n-6) were increased by the hepatocarcinogenic treatment, and this effect was further accentuated in the EPO rats. These results suggest that hepatocarcinogenesis may suppress the activity of delta-5-desaturase, which may be one of the reasons why tumor cell membranes have low levels of long chain fatty acids, especially 20:4n-6 cells, and have an impaired capacity to undergo lipid peroxidation.

  4. Adipocyte membrane glycerol permeability is involved in the anti-adipogenic effect of conjugated linoleic acid.

    PubMed

    Martins, Susana V; Madeira, Ana; Lopes, Paula A; Pires, Virgínia M R; Alfaia, Cristina M; Prates, José A M; Moura, Teresa; Soveral, Graça

    2015-03-06

    Conjugated linoleic acid (CLA), a group of minor fatty acids from ruminant origin, has long been recognized as a body fat lowering agent. Given the trans(t)10,cis(c)12-CLA well documented interference on lipolysis, we hypothesized for adipocytes altered permeation to glycerol when supplemented with this isomer. 3T3-L1 murine differentiated adipocytes were medium supplemented with linoleic acid (LA) and individual or combined c9,t11 and t10,c12-CLA isomers. Adipocytes treated with the t10,c12-CLA isomer and CLA mixture showed reduced triacylglycerols content (p < 0.001), re-enforcing the t10,c12-CLA as the anti-adipogenic CLA isomer. This finding was supported by decreased Δ9-desaturase index and adipocyte differentiation markers for the t10,c12-CLA group (p < 0.001), which suggest reduced lipogenesis and differentiation, respectively. The glycerol permeability was higher in all CLA treated cells compared to control and LA groups (p < 0.05). The increase in glycerol permeability agrees with both reduced triacylglycerols and non-osmotic cellular volume in the t10,c12-CLA and CLA mixture groups. Taken together, our data suggest that the increased adipocyte plasma membrane glycerol fluxes may be part of the anti-adipogenic response to CLA treatments.

  5. A metabolic engineering strategy for producing conjugated linoleic acids using the oleaginous yeast Yarrowia lipolytica.

    PubMed

    Imatoukene, Nabila; Verbeke, Jonathan; Beopoulos, Athanasios; Idrissi Taghki, Abdelghani; Thomasset, Brigitte; Sarde, Claude-Olivier; Nonus, Maurice; Nicaud, Jean-Marc

    2017-03-29

    Conjugated linoleic acids (CLAs) have been found to have beneficial effects on human health when used as dietary supplements. However, their availability is limited because pure, chemistry-based production is expensive, and biology-based fermentation methods can only create small quantities. In an effort to enhance microbial production of CLAs, four genetically modified strains of the oleaginous yeast Yarrowia lipolytica were generated. These mutants presented various genetic modifications, including the elimination of β-oxidation (pox1-6∆), the inability to store lipids as triglycerides (dga1∆ dga2∆ are1∆ lro1∆), and the overexpression of the Y. lipolytica ∆12-desaturase gene (YlFAD2) under the control of the constitutive pTEF promoter. All strains received two copies of the pTEF-oPAI or pPOX-oPAI expression cassettes; PAI encodes linoleic acid isomerase in Propionibacterium acnes. The strains were cultured in neosynthesis or bioconversion medium in flasks or a bioreactor. The strain combining the three modifications mentioned above showed the best results: when it was grown in neosynthesis medium in a flask, CLAs represented 6.5% of total fatty acids and in bioconversion medium in a bioreactor, and CLA content reached 302 mg/L. In a previous study, a CLA degradation rate of 117 mg/L/h was observed in bioconversion medium. Here, by eliminating β-oxidation, we achieved a much lower rate of 1.8 mg/L/h.

  6. Omega-3 Polyunsaturated Fatty Acids Attenuate Fibroblast Activation and Kidney Fibrosis Involving MTORC2 Signaling Suppression.

    PubMed

    Zeng, Zhifeng; Yang, Haiyuan; Wang, Ying; Ren, Jiafa; Dai, Yifan; Dai, Chunsun

    2017-04-10

    Epidemiologic studies showed the correlation between the deficiency of omega-3 polyunsaturated fatty acids (n-3 PUFAs) and the progression of chronic kidney diseases (CKD), however, the role and mechanisms for n-3 PUFAs in protecting against kidney fibrosis remain obscure. In this study, NRK-49F cells, a rat kidney interstitial fibroblast cell line, were stimulated with TGFβ1. A Caenorhabditis elegans fat-1 transgenic mouse model in which n-3 PUFAs are endogenously produced from n-6 PUFAs owing to the expression of n-3 fatty acid desaturase were deployed. Docosahexaenoic acid (DHA), one member of n-3 PUFAs family, could suppress TGFβ1-induced fibroblast activation at a dose and time dependent manner. Additionally, DHA could largely inhibit TGFβ1-stimulated Akt but not S6 or Smad3 phosphorylation at a time dependent manner. To decipher the role for n-3 PUFAs in protecting against kidney fibrosis, fat-1 transgenic mice were operated with unilateral ureter obstruction (UUO). Compared to the wild types, fat-1 transgenics developed much less kidney fibrosis and inflammatory cell accumulation accompanied by less p-Akt (Ser473), p-Akt (Thr308), p-S6 and p-Smad3 in kidney tissues at day 7 after UUO. Thus, n-3 PUFAs can attenuate fibroblast activation and kidney fibrosis, which may be associated with the inhibition of mTORC2 signaling.

  7. Synergistic Effect of Oleanolic Acid on Aminoglycoside Antibiotics against Acinetobacter baumannii

    PubMed Central

    Shin, Bora; Park, Woojun

    2015-01-01

    Difficulties involved in treating drug-resistant pathogens have created a need for new therapies. In this study, we investigated the possibility of using oleanolic acid (OA), a natural pentacyclic triterpenoid, as a natural adjuvant for antibiotics against Acinetobacter baumannii. High concentrations of OA can kill cells, partly because it generates reactive oxygen species. Measurement of the fractional inhibitory concentration (FIC) for OA and time-kill experiments demonstrated that it only synergizes with aminoglycoside antibiotics (e.g., gentamicin, kanamycin). Other classes of antibiotics (e.g., ampicillin, rifampicin, norfloxacin, chloramphenicol, and tetracycline) have no interactions with OA. Microarray and quantitative reverse transcription-PCR analysis indicated that genes involved in ATP synthesis and cell membrane permeability, the gene encoding glycosyltransferase, peptidoglycan-related genes, phage-related genes, and DNA repair genes were upregulated under OA. OA highly induces the expression of adk, which encodes an adenylate kinase, and des6, which encodes a linoleoyl-CoA desaturase, and deletion of these genes increased FICs; these observations indicate that adk and des6 are involved in the synergism of OA with aminoglycosides. Data obtained using 8-anilino-1-naphthalenesulfonic acid, fluorescence-conjugated gentamicin, and membrane fatty acid analysis indicates that adk and des6 are involved in changes in membrane permeability. Proton-motive force and ATP synthesis tests show that those genes are also involved in energy metabolism. Taken together, our data show that OA boosts aminoglycoside uptake by changing membrane permeability and energy metabolism in A. baumannii. PMID:26360766

  8. The Role of the Novel Lipokine Palmitoleic Acid in Health and Disease.

    PubMed

    Frigolet, María E; Gutiérrez-Aguilar, Ruth

    2017-01-01

    The monounsaturated fatty acid palmitoleate (palmitoleic acid) is one of the most abundant fatty acids in serum and tissues, particularly adipose tissue and liver. Its endogenous production by stearoyl-CoA desaturase 1 gives rise to its cis isoform, cis-palmitoleate. Although trans-palmitoleate is also synthesized in humans, it is mainly found as an exogenous source in ruminant fat and dairy products. Recently, palmitoleate was considered to be a lipokine based on evidence demonstrating its release from adipose tissue and its metabolic effects on distant organs. After this finding, research has been performed to determine whether palmitoleate has beneficial effects on metabolism and to elucidate the underlying mechanisms. Thus, the aim of this work was to review the current status of knowledge about palmitoleate, its metabolism, and its influence on metabolic abnormalities. Results have shown mixed cardiovascular effects, direct or inverse correlations with obesity, and hepatosteatosis, but a significant amelioration or prevention of insulin resistance and diabetes. Finally, the induction of palmitoleate release from adipose tissue, dietary intake, and its supplementation are all interventions with a potential impact on certain metabolic diseases.

  9. Omega-3 Polyunsaturated Fatty Acids Attenuate Fibroblast Activation and Kidney Fibrosis Involving MTORC2 Signaling Suppression

    PubMed Central

    Zeng, Zhifeng; Yang, Haiyuan; Wang, Ying; Ren, Jiafa; Dai, Yifan; Dai, Chunsun

    2017-01-01

    Epidemiologic studies showed the correlation between the deficiency of omega-3 polyunsaturated fatty acids (n-3 PUFAs) and the progression of chronic kidney diseases (CKD), however, the role and mechanisms for n-3 PUFAs in protecting against kidney fibrosis remain obscure. In this study, NRK-49F cells, a rat kidney interstitial fibroblast cell line, were stimulated with TGFβ1. A Caenorhabditis elegans fat-1 transgenic mouse model in which n-3 PUFAs are endogenously produced from n-6 PUFAs owing to the expression of n-3 fatty acid desaturase were deployed. Docosahexaenoic acid (DHA), one member of n-3 PUFAs family, could suppress TGFβ1-induced fibroblast activation at a dose and time dependent manner. Additionally, DHA could largely inhibit TGFβ1-stimulated Akt but not S6 or Smad3 phosphorylation at a time dependent manner. To decipher the role for n-3 PUFAs in protecting against kidney fibrosis, fat-1 transgenic mice were operated with unilateral ureter obstruction (UUO). Compared to the wild types, fat-1 transgenics developed much less kidney fibrosis and inflammatory cell accumulation accompanied by less p-Akt (Ser473), p-Akt (Thr308), p-S6 and p-Smad3 in kidney tissues at day 7 after UUO. Thus, n-3 PUFAs can attenuate fibroblast activation and kidney fibrosis, which may be associated with the inhibition of mTORC2 signaling. PMID:28393852

  10. Characterization and analysis of the cotton cyclopropane fatty acid synthase family and their contribution to cyclopropane fatty acid synthesis

    SciTech Connect

    Yu X. H.; Shanklin J.; Rawat, R.

    2011-05-01

    Cyclopropane fatty acids (CPA) have been found in certain gymnosperms, Malvales, Litchi and other Sapindales. The presence of their unique strained ring structures confers physical and chemical properties characteristic of unsaturated fatty acids with the oxidative stability displayed by saturated fatty acids making them of considerable industrial interest. While cyclopropenoid fatty acids (CPE) are well-known inhibitors of fatty acid desaturation in animals, CPE can also inhibit the stearoyl-CoA desaturase and interfere with the maturation and reproduction of some insect species suggesting that in addition to their traditional role as storage lipids, CPE can contribute to the protection of plants from herbivory. Three genes encoding cyclopropane synthase homologues GhCPS1, GhCPS2 and GhCPS3 were identified in cotton. Determination of gene transcript abundance revealed differences among the expression of GhCPS1, 2 and 3 showing high, intermediate and low levels, respectively, of transcripts in roots and stems; whereas GhCPS1 and 2 are both expressed at low levels in seeds. Analyses of fatty acid composition in different tissues indicate that the expression patterns of GhCPS1 and 2 correlate with cyclic fatty acid (CFA) distribution. Deletion of the N-terminal oxidase domain lowered GhCPS's ability to produce cyclopropane fatty acid by approximately 70%. GhCPS1 and 2, but not 3 resulted in the production of cyclopropane fatty acids upon heterologous expression in yeast, tobacco BY2 cell and Arabidopsis seed. In cotton GhCPS1 and 2 gene expression correlates with the total CFA content in roots, stems and seeds. That GhCPS1 and 2 are expressed at a similar level in seed suggests both of them can be considered potential targets for gene silencing to reduce undesirable seed CPE accumulation. Because GhCPS1 is more active in yeast than the published Sterculia CPS and shows similar activity when expressed in model plant systems, it represents a strong candidate gene for

  11. Evidence for cytochrome b5 as an electron donor in ricinoleic acid biosynthesis in microsomal preparations from developing castor bean (Ricinus communis L.).

    PubMed Central

    Smith, M A; Jonsson, L; Stymne, S; Stobart, K

    1992-01-01

    The major b-type cytochrome in microsomal membrane preparations from developing endosperm of castor bean (Ricinus communis) was cytochrome b5. Cytochrome P-450 was also present. The microsomal membranes had delta 12-hydroxylase activity and catalysed the NAD(P)H-dependent hydroxylation of oleate to yield ricinoleic acid. CO had no effect on the hydroxylase activity. Rabbit polyclonal antibodies were raised against the hydrophilic cytochrome b5 fragment purified from cauliflower (Brassica oleracea) floret microsomes. The anti-(cytochrome b5) IgG inhibited delta 12-hydroxylase, delta 12-desaturase and cytochrome c reductase activity in the microsomes. The results indicate that electrons from NAD(P)H were transferred to the site of hydroxylation via cytochrome b5 and that cytochrome P-450 was not involved. Images Fig. 1. PMID:1417766

  12. Plasma fatty acid composition in French-Canadian children with non-alcoholic fatty liver disease: Effect of n-3 PUFA supplementation.

    PubMed

    Spahis, S; Alvarez, F; Dubois, J; Ahmed, N; Peretti, N; Levy, E

    2015-08-01

    Non-alcoholic fatty liver disease (NAFLD) represents one of the most common causes of liver disease worldwide. As the NAFLD pathogenesis is associated with diet and lifestyle, the aims of the present work are to assess fatty acid (FA) composition in NAFLD young French-Canadian, to determine whether treatment with n-3 FA improves the plasma FA profile, and to define the time on the effectiveness of n-3 FA supplementation. Baseline characteristics of the NAFLD subjects show increased, anthropometric and biochemical parameters. Their plasma FA composition is characterized by a percent increase in total n-6 FA and a high proportion of saturated and total monounsaturated FA, as well as a decrease in Δ5 and increase in Δ6 desaturases. In conclusion, our results document for the first time the composition of plasma FAs in NAFLD young French Canadian and the efficacy of 3-month supplementation to improve the proportion of n-3 FA in their plasma.

  13. Obeticholic Acid

    MedlinePlus

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  14. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  15. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  16. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  17. Ascorbic Acid

    MedlinePlus

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  18. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  19. Amino acids

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  20. Effect of ration size on fillet fatty acid composition, phospholipid allostasis and mRNA expression patterns of lipid regulatory genes in gilthead sea bream (Sparus aurata).

    PubMed

    Benedito-Palos, Laura; Calduch-Giner, Josep A; Ballester-Lozano, Gabriel F; Pérez-Sánchez, Jaume

    2013-04-14

    The effect of ration size on muscle fatty acid (FA) composition and mRNA expression levels of key regulatory enzymes of lipid and lipoprotein metabolism have been addressed in juveniles of gilthead sea bream fed a practical diet over the course of an 11-week trial. The experimental setup included three feeding levels: (i) full ration until visual satiety, (ii) 70 % of satiation and (iii) 70 % of satiation with the last 2 weeks at the maintenance ration. Feed restriction reduced lipid content of whole body by 30 % a