Science.gov

Sample records for affects liver desaturase

  1. Alternation of plasma fatty acids composition and desaturase activities in children with liver steatosis

    PubMed Central

    Su, Hui-Min; Yao, Tsung-Chieh; Kuo, Ming-Ling; Lai, Ming-Wei; Tsai, Ming-Han; Huang, Jing-Long

    2017-01-01

    Objective The aim of this study was to investigate changes in plasma fatty acids proportions and estimated desaturase activities for variable grading of liver steatosis in children. Methods In total, 111 schoolchildren (aged 8–18 years) were included in the analysis from March 2015 to August 2016. Anthropometric evaluation, liver ultrasound examination and scoring for nonalcoholic fatty liver disease (NAFLD score = 0–6), and biochemical and plasma fatty acids analysis were performed. We compared the composition ratio of fatty acids between children with high-grade liver steatosis (NAFLD score = 4–6), low-grade liver steatosis (NAFLD score = 1–3), and healthy controls (NAFLD score = 0). In addition, correlation coefficients (r) between NAFLD score, metabolic variables, and estimated activity of desaturase indices (stearoyl-coenzyme A desaturase-1 (SCD1), delta-5 and delta-6 desaturase) were calculated. Results Compared with healthy controls, children with liver steatosis showed a higher proportion of monounsaturated fatty acids (21.16 ± 2.81% vs. 19.68 ± 2.71%, p = 0.024). In addition, children with high- grade liver steatosis exhibited higher proportions of palmitic acid (C16:0), palmitoleic acid (C16:1n-7), dihomo-γ-linolenic acid (C20:3n-6), adrenic acid (C22:4n-6), and docosapentaenoic acid (C22:5n-6); and lower proportions of eicosapentaenoic acid (C20:5n-3) (P< 0.05). In all subjects, the NAFLD score was positively correlated with body mass index (BMI) (kg/m2) (r = 0.696), homeostasis model of assessment ratio–index (HOMA-IR) (r = 0.510), SCD1(16) (r = 0.273), and the delta-6 index (r = 0.494); and inversely associated with the delta-5 index (r = -0.443). Conclusion Our current data suggested that children with liver steatosis was highly associated with obesity, and insulin resistance. In addition, increased endogenous lipogenesis through altered desaturase activity may contribute to the progression of liver steatosis in children. PMID:28759573

  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. 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. Copyright © 2014 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  5. Pomegranate seed oil influences the fatty acids profile and reduces the activity of desaturases in livers of Sprague-Dawley rats.

    PubMed

    Białek, Agnieszka; Stawarska, Agnieszka; Bodecka, Joanna; Białek, Małgorzata; Tokarz, Andrzej

    2017-07-01

    The aim of our study was to compare the influence of diet supplementation with pomegranate seed oil - as conjugated linolenic acids (CLnA) source, or conjugated linoleic acids (CLA) and to examine the mechanism of their activity. The content of fatty acids, levels of biomarkers of lipids' oxidation and the activity of key enzymes catalyzing lipids metabolism were measured. Obtained results revealed that conjugated fatty acids significantly decrease the activity of Δ5-desaturase (p=0.0001) and Δ6-desaturase (p=0.0008) and pomegranate seed oil reduces their activity in the most potent way. We confirmed that diet supplementation with pomegranate seed oil - a rich source of punicic acid leads to the increase of cis-9, trans-11 CLA content in livers (p=0.0003). Lack of side effects and beneficial influence on desaturases activity and fatty acids profile claim pomegranate seed oil to become interesting alternative for CLA as functional food. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Dietary arachidonic acid and docosahexaenoic acid regulate liver fatty acid desaturase (FADS) alternative transcript expression in suckling piglets.

    PubMed

    Wijendran, Vasuki; Downs, Ian; Srigley, Cynthia Tyburczy; Kothapalli, Kumar S D; Park, Woo Jung; Blank, Bryant S; Zimmer, J Paul; Butt, C M; Salem, Norman; Brenna, J Thomas

    2013-10-01

    Molecular regulation of fatty acid desaturase (Fads) gene expression by dietary arachidonic acid (ARA) and docosahexaenoic acid (DHA) during early post-natal period, when the demand for long chain polyunsaturated fatty acids (LC-PUFA) is very high, has not been well defined. The objective of the current study was to determine regulation of liver Fads1, Fads2 and Fads3 classical (CS) and alternative transcripts (AT) expression by dietary ARA and DHA, within the physiological range present in human breast milk, in suckling piglets. Piglets were fed one of six milk replacer formula diets (formula-reared groups, FR) with varying ARA and DHA content from days 3-28 of age. The ARA/DHA levels of the six formula diets were as follows (% total fatty acid, FA/FA): (A1) 0.1/1.0; (A2) 0.53/1.0; (A3-D3) 0.69/1.0; (A4) 1.1/1.0; (D2) 0.67/0.62; and (D1) 0.66/0.33. The control maternal-reared (MR) group remained with the dam. Fads1 expression was not significantly different between FR and MR groups. Fads2 expression was down-regulated significantly in diets with 1:1 ratio of ARA:DHA, compared to MR. Fads2 AT1 expression was highly correlated to Fads2 expression. Fads3 AT7 was the only Fads3 transcript sensitive to dietary LC-PUFA intake and was up-regulated in the formula diets with lowest ARA and DHA contents compared to MR. Thus, the present study provides evidence that the proportion of dietary ARA:DHA is a significant determinant of Fads2 expression and LC-PUFA metabolism during the early postnatal period. Further, the data suggest that Fads3 AT7 may have functional significance when dietary supply of ARA and DHA are low during early development. © 2013 Elsevier Ltd. All rights reserved.

  7. Temperature and metal exposure affect membrane fatty acid composition and transcription of desaturases and elongases in fathead minnow muscle and brain.

    PubMed

    Fadhlaoui, Mariem; Pierron, Fabien; Couture, Patrice

    2018-02-01

    In this study, we tested the hypothesis that metal exposure affected the normal thermal response of cell membrane FA composition and of elongase and desaturase gene transcription levels. To this end, muscle and brain membrane FA composition and FA desaturase (fads2, degs2 and scd2) and elongase (elovl2, elovl5 and elovl6) gene transcription levels were analyzed in fathead minnows (Pimephales promelas) acclimated for eight weeks to 15, 25 or 30°C exposed or not to cadmium (Cd, 6μg/l) or nickel (Ni, 450 6μg/l). The response of membrane FA composition to temperature variations or metal exposure differed between muscle and brain. In muscle, an increase of temperature induced a decrease of polyunsaturated FA (PUFA) and an increase of saturated FA (SFA) in agreement with the current paradigm. Although a similar response was observed in brain between 15 and 25°C, at 30°C, brain membrane unsaturation was higher than predicted. In both tissues, metal exposure affected the normal thermal response of membrane FA composition. The transcription of desaturases and elongases was higher in the brain and varied with acclimation temperature and metal exposure but these variations did not generally reflect changes in membrane FA composition. The mismatch between gene transcription and membrane composition highlights that several levels of control other than gene transcription are involved in adjusting membrane FA composition, including post-transcriptional regulation of elongases and desaturases and de novo phospholipid biosynthesis. Our study also reveals that metal exposure affects the mechanisms involved in adjusting cell membrane FA composition in ectotherms. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Omega-3 Fatty Acid Deficiency Increases Stearoyl-CoA Desaturase Expression and Activity Indices in Rat Liver: Positive Association with Non-Fasting Plasma Triglyceride Levels

    PubMed Central

    Hofacer, Rylon; Magrisso, I. Jack; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Benoit, Stephen C.; McNamara, Robert K.

    2011-01-01

    Although omega-3 (n-3) fatty acids negatively regulate triglyceride biosynthesis, the mechanisms mediating this effect are poorly understood, and emerging evidence suggests that stearoyl-CoA desaturase (Scd1) is required for de novo triglyceride biosynthesis. To investigate this mechanism, we determined the effects of perinatal n-3 deficiency and postnatal repletion on rat liver Scd1 mRNA expression and activity indices (liver 16:1/16:0 & 18:1/18:0 ratios), and determined relationships with postprandial (non-fasting) plasma triglyceride levels. Rats were fed conventional diets with or without the n-3 fatty acid precursor α-linolenic acid (ALA, 18:3n-3) during perinatal development (E0-P100), and a subset of rats fed the ALA− diet were switched to the ALA+ diet post-weaning (P21-P100, repletion). Compared with controls, rats fed the ALA− diet exhibited significantly lower liver long-chain n-3 fatty acid compositions and elevations in monounsaturated fatty acid composition, both of which were normalized in repleted rats. Liver Scd1 mRNA expression and activity indices (16:1/16:0 & 18:1/18:0 ratios) were significantly greater in n-3 deficient rats compared with controls and repleted rats. Among all rats, liver Scd1 mRNA expression was positively correlated with liver 18:1/18:0 and 16:1/16:0 ratios. Plasma triglyceride levels, but not glucose or insulin levels, were significantly greater in n-3 deficient rats compared with controls and repleted rats. Liver Scd1 mRNA expression and activity indices were positively correlated with plasma triglyceride levels. These preclinical findings demonstrate that n-3 fatty acid status is an important determinant of liver Scd1 mRNA expression and activity, and suggest that down-regulation of Scd1 is a mechanism by which n-3 fatty acids repress constitutive triglyceride biosynthesis. PMID:22047910

  9. Omega-3 fatty acid deficiency selectively up-regulates delta6-desaturase expression and activity indices in rat liver: prevention by normalization of omega-3 fatty acid status.

    PubMed

    Hofacer, Rylon; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Magrisso, I Jack; Benoit, Stephen C; McNamara, Robert K

    2011-09-01

    This study investigated the effects of perinatal dietary omega-3 (n-3) fatty acid depletion and subsequent repletion on the expression of genes that regulate long-chain (LC) polyunsaturated fatty acid biosynthesis in rat liver and brain. It was hypothesized that chronic n-3 fatty acid deficiency would increase liver Fads1 and Fads2 messenger RNA (mRNA) expression/activity and that n-3 fatty acid repletion would normalize this response. Adult rats fed the n-3-free diet during perinatal development exhibited significantly lower erythrocyte, liver, and frontal cortex LCn-3 fatty acid composition and reciprocal elevations in LC omega-6 (n-6) fatty acid composition compared with controls (CONs) and repleted rats. Liver Fads2, but not Fads1, Elovl2, or Elovl5, mRNA expression was significantly greater in n-3-deficient (DEF) rats compared with CONs and was partially normalized in repleted rats. The liver 18:3n-6/18:2n-6 ratio, an index of delta6-desturase activity, was significantly greater in DEF rats compared with CON and repleted rats and was positively correlated with Fads2 mRNA expression among all rats. The liver 18:3n-6/18:2n-6 ratio, but not Fads2 mRNA expression, was also positively correlated with erythrocyte and frontal cortex LCn-6 fatty acid compositions. Neither Fads1 or Fads2 mRNA expression was altered in brain cortex of DEF rats. These results confirm previous findings that liver, but not brain, delta6-desaturase expression and activity indices are negatively regulated by dietary n-3 fatty acids. Copyright © 2011 Elsevier Inc. All rights reserved.

  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

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

    2016-09-01

    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.

  11. 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

  12. Hydroxytyrosol prevents reduction in liver activity of Δ-5 and Δ-6 desaturases, oxidative stress, and depletion in long chain polyunsaturated fatty acid content in different tissues of high-fat diet fed mice.

    PubMed

    Valenzuela, Rodrigo; Echeverria, Francisca; Ortiz, Macarena; Rincón-Cervera, Miguel Ángel; Espinosa, Alejandra; Hernandez-Rodas, María Catalina; Illesca, Paola; Valenzuela, Alfonso; Videla, Luis A

    2017-04-11

    Eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n-6) are long-chain polyunsaturated fatty acids (LCPUFAs) with relevant roles in the organism. EPA and DHA are synthesized from the precursor alpha-linolenic acid (ALA, C18:3n-3), whereas AA is produced from linoleic acid (LA, C18:2n-6) through the action of Δ5 and Δ6-desaturases. High-fat diet (HFD) decreases the activity of both desaturases and LCPUFA accretion in liver and other tissues. Hydroxytyrosol (HT), a natural antioxidant, has an important cytoprotective effects in different cells and tissues. Male mice C57BL/6 J were fed a control diet (CD) (10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks. Animals were daily supplemented with saline (CD) or 5 mg HT (HFD), and blood and the studied tissues were analyzed after the HT intervention. Parameters studied included liver histology (optical microscopy), activity of hepatic desaturases 5 and 6 (gas-liquid chromatography of methyl esters derivatives) and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase by spectrophotometry), oxidative stress indicators (glutathione, thiobarbituric acid reactants, and the antioxidant capacity of plasma), gene expression assays for sterol regulatory element-binding protein 1c (SREBP-1c) (qPCR and ELISA), and LCPUFA profiles in liver, erythrocyte, brain, heart, and testicle (gas-liquid chromatography). HFD led to insulin resistance and liver steatosis associated with SREBP-1c upregulation, with enhancement in plasma and liver oxidative stress status and diminution in the synthesis and storage of n-6 and n-3 LCPUFAs in the studied tissues, compared to animals given control diet. HT supplementation significantly reduced fat accumulation in liver and plasma as well as tissue metabolic alterations induced by HFD. Furthermore, a normalization of desaturase activities

  13. Stearoyl-CoA desaturase activity is elevated by the suppression of its degradation by clofibric acid in the liver of rats.

    PubMed

    Toyama, Tomoaki; Kudo, Naomi; Mitsumoto, Atsushi; Hibino, Yasuhide; Tsuda, Tadashi; Kawashima, Yoichi

    2007-04-01

    A mechanism by which fibrates control stearoyl-CoA desaturase (SCD) in the liver was studied. Treatment of rats with 2-(4-chlorophenoxy)-2-methylpropionic acid (clofibric acid) or feeding of a fat-free diet markedly elevated hepatic activity of SCD. Both the treatment with clofibric acid and the feeding of the fat-free diet caused an increase in the steady-state level of SCD1 mRNA and enhanced transcriptional rate. The half-lives of SCD for control rats, rats treated with clofibric acid rats, and rats fed the fat-free diet were estimated to be 2.0, 3.9, and 1.9 h, respectively. Activity of palmitoyl-CoA chain elongase (PCE) was increased by both clofibric acid treatment and feeding of the fat-free diet as was observed with SCD. Steady-state level of rat fatty acid elongase 2 mRNA was increased by the treatment with clofibric acid or feeding of fat-free diet, although the transcriptional rate was not altered. Different from SCD, PCE was highly stable and its half-life was not changed by either clofibric acid or fat-free diet. These results strongly suggest that the decreased degradation of SCD is responsible for the increase in its activity in addition to increased transcription of SCD1 in the rats treated with clofibric acid.

  14. Hepatic delta 6-desaturase activity in lean and genetically obese ob/ob mice.

    PubMed Central

    Hughes, S; York, D A

    1985-01-01

    Hepatic delta 6-desaturase activity is primarily located in the mitochondrial fraction in mice. Both delta 6- and delta 5-desaturase activities are increased in the liver of young (6-week-old) obese mice. The increase in hepatic delta 6-desaturase activity in obese mice does not occur until weaning. Neither restriction of food intake nor hyperinsulinaemia normalize hepatic delta 6-desaturase activity of obese mice. Both cold acclimation and tri-iodothyronine (30 micrograms/day per kg) decreased hepatic delta 6-desaturase activity of obese mice to levels observed in lean mice, whereas the increase in activity in obese mice was still maintained after the induction of hypothyroidism. PMID:3977836

  15. Development of a high-throughput screening assay for stearoyl-CoA desaturase using rat liver microsomes, deuterium labeled stearoyl-CoA and mass spectrometry.

    PubMed

    Soulard, Patricia; McLaughlin, Meg; Stevens, Jessica; Connolly, Brendan; Coli, Rocco; Wang, Leyu; Moore, Jennifer; Kuo, Ming-Shang T; LaMarr, William A; Ozbal, Can C; Bhat, B Ganesh

    2008-10-03

    Several recent reports suggest that stearoyl-CoA desaturase 1 (SCD1), the rate-limiting enzyme in monounsaturated fatty acid synthesis, plays an important role in regulating lipid homeostasis and lipid oxidation in metabolically active tissues. As several manifestations of type 2 diabetes and related metabolic disorders are associated with alterations in intracellular lipid partitioning, pharmacological manipulation of SCD1 activity might be of benefit in the treatment of these disease states. In an effort to identify small molecule inhibitors of SCD1, we have developed a mass spectrometry based high-throughput screening (HTS) assay using deuterium labeled stearoyl-CoA substrate and induced rat liver microsomes. The methodology developed allows the use of a nonradioactive substrate which avoids interference by the endogenous SCD1 substrate and/or product that exist in the non-purified enzyme source. Throughput of the assay was up to twenty 384-well assay plates per day. The assay was linear with protein concentration and time, and was saturable for stearoyl-CoA substrate (K(m)=10.5 microM). The assay was highly reproducible with an average Z' value=0.6. Conjugated linoleic acid and sterculic acid, known inhibitors of SCD1, exhibited IC(50) values of 0.88 and 0.12 microM, respectively. High-throughput mass spectrometry screening of over 1.7 million compounds in compressed format demonstrated that the enzyme target is druggable. A total of 2515 hits were identified (0.1% hit rate), and 346 were confirmed active (>40% inhibition of total SCD activity at 20 microM--14% conformation rate). Of the confirmed hits 172 had IC(50) values of <10 microM, including 111 <1 microM and 48 <100 nM. A large number of potent drug-like (MW<450) hits representing six different chemical series were identified. The application of mass spectrometry to high-throughput screening permitted the development of a high-quality screening protocol for an otherwise intractable target, SCD1. Further

  16. Lipopolysaccharide derived from the rumen down-regulates stearoyl-CoA desaturase 1 expression and alters fatty acid composition in the liver of dairy cows fed a high-concentrate diet.

    PubMed

    Xu, Tianle; Tao, Hui; Chang, Guangjun; Zhang, Kai; Xu, Lei; Shen, Xiangzhen

    2015-03-07

    Dairy cows are often fed a high-concentrate diet to meet lactating demands, yet long-term concentrate feeding induces subacute ruminal acidosis (SARA) and leads to a decrease in milk fat. Stearoyl-CoA desaturase1 (SCD1) participates in fatty acid biosynthesis in the liver of lactating ruminants. Here, we conducted this study to investigate the impact of lipopolysaccharide derived from the rumen on SCD1 expression and on fatty acid composition in the liver of dairy cows fed a high-concentrate diet. Eight multiparous mid-lactating Holstein cows (455 ± 28 kg) were randomly assigned into two groups in the experiment and were fed a low-concentrate diet (LC) or high-concentrate diet (HC) for 18 weeks. The results showed that the total volatile fatty acids and lactic acid accumulated in the rumen, leading to a decreased rumen pH and elevated lipopolysaccharides (LPSs) in the HC group. The long chain fatty acid profile in the rumen and hepatic vein was remarkably altered in the animals fed the HC diet. The triglyceride (TG), non-esterified fatty acid (NEFA) and total cholesterol (TCH) content in the plasma was significantly decreased, whereas plasma glucose and insulin levels were increased. The expression of SCD1 in the liver was significantly down-regulated in the HC group. In regards to transcriptional regulators, the expression of sterol regulatory element binding transcription factors (SREBF1c, SREBF2) and SREBP cleavage activating protein (SCAP) was down-regulated, while peroxisome proliferator-activated receptor α (PPARα) was up-regulated. These data indicate that lipopolysaccharide derived from the rumen down-regulates stearoyl-CoA desaturase 1 expression and alters fatty acid composition in the liver of dairy cows fed a high-concentrate diet.

  17. 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.

  18. Modified Acyl-ACP desaturase

    DOEpatents

    Cahoon, Edgar B.; Shanklin, John; Lindqvist, Ylva; Schneider, Gunter

    1999-03-30

    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.

  19. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, Edgar B.; Shanklin, John; Lindgvist, Ylva; Schneider, Gunter

    1998-01-06

    Disclosed is a methods 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.

  20. 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.

  1. Modified Acyl-ACP desaturase

    DOEpatents

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

    1999-03-30

    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. 2 figs.

  2. Sex-related differences in the enhancing effects of perfluoro-octanoic acid on stearoyl-CoA desaturase and its influence on the acyl composition of phospholipid in rat liver. Comparison with clofibric acid and tiadenol.

    PubMed Central

    Kawashima, Y; Uy-Yu, N; Kozuka, H

    1989-01-01

    The effects of the peroxisome proliferators clofibric acid (p-chlorophenoxyisobutyric acid), tiadenol [2,2'-(decamethylenedithio)diethanol] and perfluoro-octanoic acid (PFOA) on hepatic stearoyl-CoA desaturation in male and female rats were compared. Treatment of male rats with the three peroxisome proliferators increased markedly the activity of stearoyl-CoA desaturase. Administration of clofibric acid or tiadenol to female rats increased greatly the hepatic activity of stearoyl-CoA desaturase, the extent of the increases being slightly less pronounced than those of male rats. In contrast with the other two peroxisome proliferators, however, PFOA did not change the activity of stearoyl-CoA desaturase in female rats. Hormonal manipulations revealed that this sex-related difference in the effect of PFOA on stearoyl-CoA desaturase activity is strongly dependent on testosterone. The increase in stearoyl-CoA desaturase activity by peroxisome proliferators was not accompanied by any notable increases in the microsomal content of cytochrome b5 or the activity of NADH: cytochrome b5 reductase. The administration of the peroxisome proliferators greatly altered the acyl composition of hepatic phosphatidylcholine and phosphatidylethanolamine (namely the proportions of C18:1 and C20:3,n-9 fatty acids increased in both phospholipids), and the alterations were partially associated with the increase in stearoyl-CoA desaturase activity. PMID:2574572

  3. 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

  4. Dietary starch types affect liver nutrient metabolism of finishing pigs.

    PubMed

    Xie, Chen; Li, Yanjiao; Li, Jiaolong; Zhang, Lin; Zhou, Guanghong; Gao, Feng

    2017-09-01

    This study aimed to evaluate the effect of different starch types on liver nutrient metabolism of finishing pigs. In all ninety barrows were randomly allocated to three diets with five replicates of six pigs, containing purified waxy maize starch (WMS), non-waxy maize starch (NMS) and pea starch (PS) (the amylose to amylopectin ratios were 0·07, 0·19 and 0·28, respectively). After 28 d of treatments, two per pen (close to the average body weight of the pen) were weighed individually, slaughtered and liver samples were collected. Compared with the WMS diet, the PS diet decreased the activities of glycogen phosphorylase, phosphoenolpyruvate carboxykinase and the expression of phosphoenolpyruvate carboxykinase 1 in liver (P0·05). Compared with the WMS diet, the PS diet reduced the expressions of glutamate dehydrogenase and carbamoyl phosphate synthetase 1 in liver (P<0·05). PS diet decreased the expression of the insulin receptor, and increased the expressions of mammalian target of rapamycin complex 1 and ribosomal protein S6 kinase β-1 in liver compared with the WMS diet (P<0·05). These findings indicated that the diet with higher amylose content could down-regulate gluconeogenesis, and cause less fat deposition and more protein deposition by affecting the insulin/PI3K/protein kinase B signalling pathway in liver of finishing pigs.

  5. Cold affects the transcription of fatty acid desaturases and oil quality in the fruit of Olea europaea L. genotypes with different cold hardiness

    PubMed Central

    Matteucci, M.; D'Angeli, S.; Errico, S.; Lamanna, R.; Perrotta, G.; Altamura, M. M.

    2011-01-01

    The olive tree lacks dormancy and is low temperature sensitive, with differences in cold tolerance and oil quality among genotypes. The oil is produced in the drupe, and the unsaturated fatty acids contribute to its quality. The aim of the present research was to investigate the relationship among development, cold response, expression of fatty acid desaturase (FAD) genes, and unsaturated fatty acid composition in drupes belonging to genotypes differing in leaf cold tolerance, but producing good oil (i.e. the non-hardy Moraiolo, the semi-hardy Frantoio, and the hardy Canino). In all genotypes, cold sensitivity, evaluated by cold-induced transient increases in cytosolic calcium, was high in the epi-mesocarp cells before oil body formation, and decreased during oil biogenesis. However, genotype-dependent differences in cold sensitivity appeared at the end of oil production. Genotype-dependent differences in FAD2.1, FAD2.2, FAD6, and FAD7 expression levels occurred in the epi-mesocarp cells during the oleogenic period. However, FAD2.1 and FAD7 were always the highest in the first part of this period. FAD2.2 and FAD7 increased after cold applications during oleogenesis, independently of the genotype. Unsaturated fatty acids increased in the drupes of the non-hardy genotype, but not in those of the hardy one, after cold exposure at the time of the highest FAD transcription. The results show a direct relationship between FAD expression and lipid desaturation in the drupes of the cold-sensitive genotype, and an inverse relationship in those of the cold-resistant genotype, suggesting that drupe cold acclimation requires a fine FAD post-transcriptional regulation. Hypotheses relating FAD desaturation to storage and membrane lipids, and genotype cold hardiness are discussed. PMID:21357772

  6. 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

  7. Molecular cloning and sequence analysis of stearoyl-CoA desaturase in milkfish, Chanos chanos.

    PubMed

    Hsieh, S L; Liao, W L; Kuo, C M

    2001-12-01

    Stearoyl-CoA desaturase (EC 1.14.99.5) is a key enzyme in the biosynthesis of polyunsaturated fatty acids and the maintenance of the homeoviscous fluidity of biological membranes. The stearoyl-CoA desaturase cDNA in milkfish (Chanos chanos) was cloned by RT-PCR and RACE, and it was compared with the stearoyl-CoA desaturase in cold-tolerant teleosts, common carp and grass carp. Nucleotide sequence analysis revealed that the cDNA clone has a 972-bp open reading frame encoding 323 amino acid residues. Alignments of the deduced amino acid sequence showed that the milkfish stearoyl-CoA desaturase shares 79% and 75% identity with common carp and grass carp, and 63%-64% with other vertebrates such as sheep, hamsters, rats, mice, and humans. Like common carp and grass carp, the deduced amino acid sequence in milkfish well conserves three histidine cluster motifs (one HXXXXH and two HXXHH) that are essential for catalysis of stearoyl-CoA desaturase activity. However, RT-PCR analysis showed that stearoyl-CoA desaturase expression in milkfish is detected in the tissues of liver, muscle, kidney, brain, and gill, and more expression sites were found in milkfish than in common carp and grass carp. Phylogenic relationships among the deduced stearoyl-CoA desaturase amino acid sequence in milkfish and those in other vertebrates showed that the milkfish stearoyl-CoA desaturase amino acid sequence is phylogenetically closer to those of common carp and grass carp than to other higher vertebrates.

  8. 9 CFR 311.31 - Livers affected with carotenosis; livers designated as “telangiectatic,” “sawdust,” or “spotted.”

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designated as “telangiectatic,” “sawdust,” or “spotted.” (a) Livers affected with carotenosis shall be condemned. (b) Cattle livers and calf livers showing the conditions sometimes designated as “telangiectatic... are necessary for inspection. (c) “Telangiectatic,” “sawdust,” or “spotted” livers and parts of livers...

  9. 9 CFR 311.31 - Livers affected with carotenosis; livers designated as “telangiectatic,” “sawdust,” or “spotted.”

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designated as “telangiectatic,” “sawdust,” or “spotted.” (a) Livers affected with carotenosis shall be condemned. (b) Cattle livers and calf livers showing the conditions sometimes designated as “telangiectatic... are necessary for inspection. (c) “Telangiectatic,” “sawdust,” or “spotted” livers and parts of livers...

  10. 9 CFR 311.31 - Livers affected with carotenosis; livers designated as “telangiectatic,” “sawdust,” or “spotted.”

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designated as “telangiectatic,” “sawdust,” or “spotted.” (a) Livers affected with carotenosis shall be condemned. (b) Cattle livers and calf livers showing the conditions sometimes designated as “telangiectatic... are necessary for inspection. (c) “Telangiectatic,” “sawdust,” or “spotted” livers and parts of livers...

  11. 9 CFR 311.31 - Livers affected with carotenosis; livers designated as “telangiectatic,” “sawdust,” or “spotted.”

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... designated as “telangiectatic,” “sawdust,” or “spotted.” (a) Livers affected with carotenosis shall be condemned. (b) Cattle livers and calf livers showing the conditions sometimes designated as “telangiectatic... are necessary for inspection. (c) “Telangiectatic,” “sawdust,” or “spotted” livers and parts of livers...

  12. Histone acetyltransferase general control non-repressed protein 5 (GCN5) affects the fatty acid composition of Arabidopsis thaliana seeds by acetylating fatty acid desaturase3 (FAD3).

    PubMed

    Wang, Tianya; Xing, Jiewen; Liu, Xinye; Liu, Zhenshan; Yao, Yingyin; Hu, Zhaorong; Peng, Huiru; Xin, Mingming; Zhou, Dao-Xiu; Zhang, Yirong; Ni, Zhongfu

    2016-12-01

    Seed oils are important natural resources used in the processing and preparation of food. Histone modifications represent key epigenetic mechanisms that regulate gene expression, plant growth and development. However, histone modification events during fatty acid (FA) biosynthesis are not well understood. Here, we demonstrate that a mutation of the histone acetyltransferase GCN5 can decrease the ratio of α-linolenic acid (ALA) to linoleic acid (LA) in seed oil. Using RNA-Seq and ChIP assays, we identified FAD3, LACS2, LPP3 and PLAIIIβ as the targets of GCN5. Notably, the GCN5-dependent H3K9/14 acetylation of FAD3 determined the expression levels of FAD3 in Arabidopsis thaliana seeds, and the ratio of ALA/LA in the gcn5 mutant was rescued to the wild-type levels through the overexpression of FAD3. The results of this study indicated that GCN5 modulated FA biosynthesis by affecting the acetylation levels of FAD3. We provide evidence that histone acetylation is involved in FA biosynthesis in Arabidopsis seeds and might contribute to the optimization of the nutritional structure of edible oils through epigenetic engineering. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  13. Regulation of hepatic fatty acid elongase and desaturase expression in diabetes and obesity

    PubMed Central

    Wang, Yun; Botolin, Daniela; Xu, Jinghua; Christian, Barbara; Mitchell, Ernestine; Jayaprakasam, Bolleddula; Nair, Muraleedharan; Peters, Jeffery M.; Busik, Julia; Olson, L. Karl; Jump, Donald B.

    2009-01-01

    Fatty acid elongases and desaturases play an important role in hepatic and whole body lipid composition. We examined the role that key transcription factors played in the control of hepatic elongase and desaturase expression. Studies with peroxisome proliferator-activated receptor α (PPARα)-deficient mice establish that PPARα was required for WY14643-mediated induction of fatty acid elongase-5 (Elovl-5), Elovl-6, and all three desaturases [Δ5 desaturase (Δ5D), Δ6D, and Δ9D]. Increased nuclear sterol-regulatory element binding protein-1 (SREBP-1) correlated with enhanced expression of Elovl-6, Δ5D, Δ6D, and Δ9D. Only Δ9D was also regulated independently by liver X receptor (LXR) agonist. Glucose induction of L-type pyruvate kinase, Δ9D, and Elovl-6 expression required the carbohydrate-regulatory element binding protein/MAX-like factor X (ChREBP/MLX) heterodimer. Suppression of Elovl-6 and Δ9D expression in livers of streptozotocin-induced diabetic rats and high fat-fed glucose-intolerant mice correlated with low levels of nuclear SREBP-1. In leptin-deficient obese mice (Lepob/ob), increased SREBP-1 and MLX nuclear content correlated with the induction of Elovl-5, Elovl-6, and Δ9D expression and the massive accumulation of monoun-saturated fatty acids (18:1,n-7 and 18:1,n-9) in neutral lipids. Diabetes- and obesity-induced changes in hepatic lipid composition correlated with changes in elongase and desaturase expression. In conclusion, these studies establish a role for PPARα, LXR, SREBP-1, ChREBP, and MLX in the control of hepatic fatty acid elongase and desaturase expression and lipid composition. PMID:16790840

  14. Effect of seafood mediated PCB exposure on desaturase activity and PUFA profile in Faroese septuagenarians.

    PubMed

    Tøttenborg, Sandra Søgaard; Choi, Anna L; Bjerve, Kristian S; Weihe, Pal; Grandjean, Philippe

    2015-07-01

    Polychlorinated biphenyl (PCB) exposure may affect serum concentrations of polyunsaturated fatty acids (PUFAs) by inhibiting desaturases ∆5 and ∆6 that drive their synthesis from precursor fatty acids. Such changes in the composition of fatty acids may affect cardiovascular disease risk, which is thought to increase at elevated PCB exposures. This population-based cross-sectional study examined 712 Faroese men and women aged 70-74 years. The serum phospholipid fraction of fasting blood samples was used to determine the PUFA profile, including linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, eicosatrienoic acid, and other relevant fatty acids. Ratios between precursor and metabolite fatty acids were used as proxies for ∆5 and ∆6 desaturase activity. Tertiles of serum-PCB concentrations were used in multiple regression analyses to determine the association between the exposure and desaturase activity. In multiple regression models, PCB exposure was inversely related to the estimated Δ6 desaturase activity resulting in accumulation of precursor fatty acids and decrease in the corresponding product PUFAs. A positive association between PCB and Δ5 desaturation was also found. A relative increase in EA was also observed, though only in the third tertile of PCB exposure. Non-linear relationships between the exposure and the desaturase activity were not found. Consuming fish and seafood may not be translated into beneficial fatty acid profiles if the diet simultaneously causes exposure to PCBs. Although the desaturase estimates were likely influenced by dietary intakes of product PUFAs, the association between PCB exposure and ∆6 desaturase activity is plausible and may affect cardiovascular disease risk. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 9 CFR 311.31 - Livers affected with carotenosis; livers designated as “telangiectatic,” “sawdust,” or “spotted.”

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Livers affected with carotenosis; livers designated as âtelangiectatic,â âsawdust,â or âspotted.â 311.31 Section 311.31 Animals and Animal... DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.31 Livers affected with carotenosis; livers...

  16. Ozone-derived Oxysterols Affect Liver X Receptor (LXR) Signaling

    PubMed Central

    Kim, Hye-Young H.; Bauer, Rebecca N.; Fessler, Michael B.; Duncan, Kelly E.; Liu, Wei; Porter, Ned A.

    2016-01-01

    When inhaled, ozone (O3) interacts with cholesterols of airway epithelial cell membranes or the lung-lining fluid, generating chemically reactive oxysterols. The mechanism by which O3-derived oxysterols affect molecular function is unknown. Our data show that in vitro exposure of human bronchial epithelial cells to O3 results in the formation of oxysterols, epoxycholesterol-α and -β and secosterol A and B (Seco A and Seco B), in cell lysates and apical washes. Similarly, bronchoalveolar lavage fluid obtained from human volunteers exposed to O3 contained elevated levels of these oxysterol species. As expected, O3-derived oxysterols have a pro-inflammatory effect and increase NF-κB activity. Interestingly, expression of the cholesterol efflux pump ATP-binding cassette transporter 1 (ABCA1), which is regulated by activation of the liver X receptor (LXR), was suppressed in epithelial cells exposed to O3. Additionally, exposure of LXR knock-out mice to O3 enhanced pro-inflammatory cytokine production in the lung, suggesting LXR inhibits O3-induced inflammation. Using alkynyl surrogates of O3-derived oxysterols, our data demonstrate adduction of LXR with Seco A. Similarly, supplementation of epithelial cells with alkynyl-tagged cholesterol followed by O3 exposure causes observable lipid-LXR adduct formation. Experiments using Seco A and the LXR agonist T0901317 (T09) showed reduced expression of ABCA1 as compared with stimulation with T0901317 alone, indicating that Seco A-LXR protein adduct formation inhibits LXR activation by traditional agonists. Overall, these data demonstrate that O3-derived oxysterols have pro-inflammatory functions and form lipid-protein adducts with LXR, thus leading to suppressed cholesterol regulatory gene expression and providing a biochemical mechanism mediating O3-derived formation of oxidized lipids in the airways and subsequent adverse health effects. PMID:27703007

  17. Uridine Affects Liver Protein Glycosylation, Insulin Signaling, and Heme Biosynthesis

    PubMed Central

    Urasaki, Yasuyo; Pizzorno, Giuseppe; Le, Thuc T.

    2014-01-01

    Purines and pyrimidines are complementary bases of the genetic code. The roles of purines and their derivatives in cellular signal transduction and energy metabolism are well-known. In contrast, the roles of pyrimidines and their derivatives in cellular function remain poorly understood. In this study, the roles of uridine, a pyrimidine nucleoside, in liver metabolism are examined in mice. We report that short-term uridine administration in C57BL/6J mice increases liver protein glycosylation profiles, reduces phosphorylation level of insulin signaling proteins, and activates the HRI-eIF-2α-ATF4 heme-deficiency stress response pathway. Short-term uridine administration is also associated with reduced liver hemin level and reduced ability for insulin-stimulated blood glucose removal during an insulin tolerance test. Some of the short-term effects of exogenous uridine in C57BL/6J mice are conserved in transgenic UPase1 −/− mice with long-term elevation of endogenous uridine level. UPase1 −/− mice exhibit activation of the liver HRI-eIF-2α-ATF4 heme-deficiency stress response pathway. UPase1 −/− mice also exhibit impaired ability for insulin-stimulated blood glucose removal. However, other short-term effects of exogenous uridine in C57BL/6J mice are not conserved in UPase1 −/− mice. UPase1 −/− mice exhibit normal phosphorylation level of liver insulin signaling proteins and increased liver hemin concentration compared to untreated control C57BL/6J mice. Contrasting short-term and long-term consequences of uridine on liver metabolism suggest that uridine exerts transient effects and elicits adaptive responses. Taken together, our data support potential roles of pyrimidines and their derivatives in the regulation of liver metabolism. PMID:24918436

  18. How Ketamine Affects Livers of Pregnant Mice and Developing Mice?

    PubMed

    Cheung, Hoi Man; Chow, Tony Chin Hung; Yew, David Tai Wai

    2017-05-19

    It is well known that ketamine abuse can induce liver damage in adult addicts, but the effects of ketamine abuse in pregnant mothers on their offspring have received less attention. In this study, we investigated the effects of 5-day ketamine injections (30 mg/kg) to pregnant Institute for Cancer Research (ICR) mice during early gestation or mid-gestation on the aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities of the mothers and the offspring. We also looked into whether administering ketamine treatment to the mothers had any effects on the extent of fibrosis, cell proliferation and cell death in the livers of the newborns. No significant biochemical differences were found between treatment and control groups in the mothers. In the offspring, ketamine treatment mildly suppressed the gradual increase of hepatic AST activity in neonates during liver maturation. Measurements of hepatic ALP activity and lactic acid dehydrogenase (LDH) immunoreactivity revealed that ketamine treatment may lead to increased cell death. Proliferation of liver cells of the newborns was also retarded as shown by reduced proliferative cell nuclear antigen (PCNA) immunoreactivity in the ketamine groups. No obvious fibrosis was evident. Thus, we demonstrated that ketamine administration to pregnant mice suppressed hepatic development and also induced liver cell death of the offspring.

  19. Adding a purple corn extract in rats supplemented with chia oil decreases gene expression of SREBP-1c and retains Δ5 and Δ6 hepatic desaturase activity, unmodified the hepatic lipid profile.

    PubMed

    Reyna Gallegos, Sixto; Torres Arrunátegui, Génesis; Valenzuela, Rodrigo; Rincón-Cervera, Miguel Ángel; Villanueva Espinoza, María Elena

    2018-05-01

    Flavonoids upregulate gene expression of PPAR-α and underregulate the gene expression of SREBP-1c, and their intake increases the plasmatic concentration of n-3 LC-PUFAs. However, the biological mechanisms underlying these effects have not been elucidated. In this work, the effect of oral supplementation of ALA from chia (Salvia hispanica L.) seed oil and anthocyanins from a purple corn extract (PCE) on gene expression of SREBP-1c, PPAR-α and Δ5 and Δ6 desaturases (Δ5D and Δ6D), the activity of these enzymes in the liver as well as the hepatic lipid profile were evaluated in thirty-six female Sprague Dawley rats whose diet was supplemented with olive oil (OL), chia oil (CH), olive oil and PCE (OL + PCE) or chia oil and PCE (CH + PCE). Gene expression of PPAR-α was significantly higher when supplemented with CH and CH + PCE, SREBP-1c gene expression was higher when supplemented with chia oil. CH supplementation enhanced Δ5D expression whereas no significant differences between treatments were observed concerning Δ6D gene expression. Activities of both desaturases were increased by including olive oil (OL + PCE and OL), and they were found to be higher in CH + PCE respect to CH for both enzymes. The ALA and n-3 LCPUFAs hepatic content was higher with CH, decreasing the levels of AA and n-6 LCPUFAs. It is concluded that the joint action of flavonoids such as anthocyanins and ALA show an anti-adipogenic effect. Desaturase activity was inhibited by ALA and kept by the anthocyanins from PCE, thus anthocyanins would exert a protective effect on the desaturase activity but they would not affect on its gene expression, however, high doses of ALA increased the production of its metabolites, masking the effect of PCE. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Infections in patients affected by liver cirrhosis: an update.

    PubMed

    Ascione, Tiziana; Di Flumeri, Giusy; Boccia, Giovanni; De Caro, Francesco

    2017-06-01

    Patients with liver cirrhosis present an increased incidence of infections. The main cause has been founded in alterations of the enteric flora and of the intestinal barrier probably due to portal hypertension, in addition to a reticulo-endothelial system dysfunction. Furthermore, those living with cirrhosis can report a high predisposition to sepsis and septic shock, due to the excessive response of pro-inflammatory cytokines and a complessive hemodynamic derangement. By the analysis in the experimental model of the cirrhotic rat, it was demonstrated that radio-labelled Escherichia coli given by the oral route resulted in the location of the bacteria in the gut, the ascitic fluid and mesenteric lymph nodes, a phenomenon known as bacterial translocation. Bacteria encountered with the highest frequency are those colonizing the intestinal tract, such as E. coli, Klebsiella pneumoniae and Enterobacteriaceae, intracellular bacteria and parasites are reported with a lower frequency. Multi-drug resistant bacteria are cultured with the highest frequency in those with frequent hospitalisations and report both high septic shock and mortality rates. Spontaneous bacterial peritonitis (SBP) is the commonest infection in cirrhotic, estimated to occur in 10-30% of the cases with ascites. A practical approach may include administration of a protected penicillin, III generation cephalosporin or quinolones in uncomplicated cases. Instead, in complicated cases and in nosocomial SBP, administration of cephalosporin or quinolones can be burned by the high resistance rate and drugs active against ESBL-producing bacteria and multi-drug resistant Gram positive bacteria have to be considered as empiric therapy, until cultures are available. When cultures are not readily available and patients fail to improve a repeated diagnostic paracentesis should be performed. Current investigations suggest that norfloxacin 400 mg/day orally has been reported to successfully prevent SBP in patients

  1. Identification and functional analysis of delta-9 desaturase, a key enzyme in PUFA Synthesis, isolated from the oleaginous diatom Fistulifera.

    PubMed

    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 Δ(9) desaturase genes (fD9desA, fD9desB, fD9desC and fD9desD) from the oleaginous diatom Fistulifera were newly isolated and functionally characterized. The putative Δ(9) acyl-CoA desaturases in the endoplasmic reticulum (ER) showed 3 histidine clusters that are well-conserved motifs in the typical Δ(9) desaturase. Furthermore, the function of these Δ(9) desaturases was confirmed in the Saccharomyces cerevisiae ole1 gene deletion mutant (Δole1). All the putative Δ(9) acyl-CoA desaturases showed Δ(9) 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 Δ(9) 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.

  2. Association of desaturase activity and C-reactive protein in European children.

    PubMed

    Wolters, Maike; Börnhorst, Claudia; Schwarz, Heike; Risé, Patrizia; Galli, Claudio; Moreno, Luis A; Pala, Valeria; Russo, Paola; Veidebaum, Toomas; Tornaritis, Michael; Fraterman, Arno; De Henauw, Stefaan; Eiben, Gabriele; Lissner, Lauren; Molnár, Dénes; Ahrens, Wolfgang

    2017-01-01

    Desaturase enzymes influence the fatty acid (FA) composition of body tissues and their activity affects the conversion rate of saturated to monounsaturated FA and of polyunsaturated FA (PUFA) to long-chain PUFA. Desaturase activity has further been shown to be associated with inflammation. We investigate the association between delta-9 (D9D), delta-6 (D6D) and delta-5 desaturase (D5D) activity and high-sensitive C-reactive protein (CRP) in young children. In the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cohort study children were examined at baseline (T0) and after 2 y (T1). D9D, D6D, and D5D activities were estimated from T0 product-precursor FA ratios. CRP was measured at T0 and T1. In a subsample of 1,943 children with available information on FA, CRP, and covariates, the cross-sectional and longitudinal associations of desaturase activity and CRP were analyzed. Cross-sectionally, a D9D increase of 0.01 units was associated with a 11% higher risk of having a serum CRP ≥ Percentile 75 (P75) (OR, 99% CI: 1.11 (1.01; 1.22)) whereas D6D and D5D were not associated with CRP. No significant associations were observed between baseline desaturase activity and CRP 2 y later. Cross-sectionally, our results indicate a positive association of D9D and CRP independent of weight status. High D9D activity may increase the risk of subclinical inflammation which is associated with metabolic disorders. As D9D expression increases with higher intake of saturated FA and carbohydrates, dietary changes may influence D9D activity and thus CRP. However, it remains to be investigated whether there is a causal relationship between D9D activity and CRP.

  3. Hnf4α is involved in the regulation of vertebrate LC-PUFA biosynthesis: insights into the regulatory role of Hnf4α on expression of liver fatty acyl desaturases in the marine teleost Siganus canaliculatus.

    PubMed

    Wang, Shuqi; Chen, Junliang; Jiang, Danli; Zhang, Qinghao; You, Cuihong; Tocher, Douglas R; Monroig, Óscar; Dong, Yewei; Li, Yuanyou

    2018-06-01

    Long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis is an important metabolic pathway in vertebrates, especially fish, considering they are the major source of n-3 LC-PUFA in the human diet. However, most fish have only limited capability for biosynthesis of LC-PUFA. The rabbitfish (Siganus canaliculatus) is able to synthesize LC-PUFA as it has all the key enzyme activities required including Δ6Δ5 Fads2, Δ4 Fads2, Elovl5, and Elovl4. We previously reported a direct interaction between the transcription factor Hnf4α and the promoter regions of Δ4 and Δ6Δ5 Fads2, which suggested that Hnf4α was involved in the transcriptional regulation of fads2 in rabbitfish. For functionally investigating it further, a full-length cDNA of 1736-bp-encoding rabbitfish Hnf4α with 454 amino acids was cloned, which was highly expressed in intestine, followed by liver and eyes. Similar to the expression characteristics of its target genes Δ4 and Δ6Δ5 fads2, levels of hnf4α mRNA in liver and eyes were higher in fish reared at low salinity than those reared in high salinity. After the rabbitfish primary hepatocytes were, respectively, incubated with alverine, benfluorex or BI6015, which were anticipated agonists or antagonist for Hnf4α, the mRNA level of Δ6Δ5 and Δ4 fads2 displayed a similar change tendency with that of hnf4α mRNA. Furthermore, when the mRNA level of hhf4α was knocked down using siRNA, the expression of Δ6Δ5 and Δ4 fads2 also decreased. Together, these data suggest that Hnf4α is involved in the transcriptional regulation of LC-PUFA biosynthesis, specifically, by targeting Δ4 and Δ6Δ5 fads2 in rabbitfish.

  4. Identification of Plants That Inhibit Lipid Droplet Formation in Liver Cells: Rubus suavissimus Leaf Extract Protects Mice from High-Fat Diet-Induced Fatty Liver by Directly Affecting Liver Cells

    PubMed Central

    Takahashi, Tomohiro; Sugawara, Wataru; Takiguchi, Yuya; Takizawa, Kento; Nakabayashi, Ami; Nakamura, Mitsuo; Nagano-Ito, Michiyo; Ichikawa, Shinichi

    2016-01-01

    Fatty liver disease is a condition in which abnormally large numbers of lipid droplets accumulate in liver cells. Fatty liver disease induces inflammation under conditions of oxidative stress and may result in cancer. To identify plants that protect against fatty liver disease, we examined the inhibitory effects of plant extracts on lipid droplet formation in mouse hepatoma cells. A screen of 98 water extracts of plants revealed 4 extracts with inhibitory effects. One of these extracts, Rubus suavissimus S. Lee (Tien-cha or Chinese sweet tea) leaf extract, which showed strong inhibitory effects, was tested in a mouse fatty liver model. In these mouse experiments, intake of the plant extract significantly protected mice against fatty liver disease without affecting body weight gain. Our results suggest that RSE directly affects liver cells and protects them from fatty liver disease. PMID:27429636

  5. Bioengineering resistance to phytoene desaturase inhibitors in Arabidopsis thaliana

    USDA-ARS?s Scientific Manuscript database

    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...

  6. PNPLA3 I148M variant affects non-alcoholic fatty liver disease in liver transplant recipients.

    PubMed

    Liu, Zheng-Tao; Chen, Tian-Chi; Lu, Xiao-Xiao; Cheng, Jun; Xie, Hai-Yang; Zhou, Lin; Zheng, Shu-Sen

    2015-09-14

    De novo non-alcoholic fatty liver disease (NAFLD) is a common late complication for long-term survivors after liver transplantation. Genomic studies confirmed that PNPLA3 I148M and TM6SF2 E167K polymorphisms affected NAFLD susceptibility in the general population. However, this association was not validated in survivors after liver transplantation (LT). We performed a cross-sectional survey to investigate this relationship. A comprehensive survey, including anthropometric measurements, fasting venous blood sampling, ultrasound, and questionnaires was performed in the short-term. The clinical indications and patient's steatosis status before LT were collected from inpatient medical records. Sixty-five long-term recipients with a survival exceeding 10 years were enrolled in the final analysis. De novo NAFLD was more frequent in PNPLA3 GG carriers (0.33 vs 0.10 for GG vs CC + CG carriers, P = 0.018), while the genetic impact on NAFLD susceptibility was insignificant when categorized by the TM6SF2 polymorphism (0.19 in CC vs 0.14 in CT + TT carriers, P = 0.883). Multi-covariate analysis revealed that PNPLA3 exerted a significant genetic effect on de novo NAFLD following a recessive model (GG vs CC + CG, OR = 14.2, 95%CI: 1.78-113, P = 0.012). Compared to recipients with only the PNPLA3 GG allele or obesity (defined as body mass index > 25 kg/m(2)), steatosis was highly prevalent (71.4%) in PNPLA3 GG carriers with obesity. In conclusion, PNPLA3 I148M, but not TM6SF2 E167K, affects de novo NAFLD occurrence with a prominent interaction with obesity. Weight control might be a meaningful method to reduce the genetic susceptibility to NAFLD exerted by PNPLA3 variants.

  7. Mutant fatty acid desaturase and methods for directed mutagenesis

    DOEpatents

    Shanklin, John [Shoreham, NY; Whittle, Edward J [Greenport, NY

    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. FATTY ACID DESATURASE4 of Arabidopsis encodes a protein distinct from characterized fatty acid desaturases.

    PubMed

    Gao, Jinpeng; Ajjawi, Imad; Manoli, Arthur; Sawin, Andrew; Xu, Changcheng; Froehlich, John E; Last, Robert L; Benning, Christoph

    2009-12-01

    Polar membrane glycerolipids occur in a mixture of molecular species defined by a polar head group and characteristic acyl groups esterified to a glycerol backbone. A molecular species of phosphatidylglycerol specific to chloroplasts of plants carries a Delta(3-trans) hexadecenoic acid in the sn-2 position of its core glyceryl moiety. The fad4-1 mutant of Arabidopsis thaliana missing this particular phosphatidylglycerol molecular species lacks the necessary fatty acid desaturase, or a component thereof. The overwhelming majority of acyl groups associated with membrane lipids in plants contains double bonds with a cis configuration. However, FAD4 is unusual because it is involved in the formation of a trans double bond introduced close to the carboxyl group of palmitic acid, which is specifically esterified to the sn-2 glyceryl carbon of phosphatidylglycerol. As a first step towards the analysis of this unusual desaturase reaction, the FAD4 gene was identified by mapping of the FAD4 locus and coexpression analysis with known lipid genes. FAD4 encodes a predicted integral membrane protein that appears to be unrelated to classic membrane bound fatty acid desaturases based on overall sequence conservation. However, the FAD4 protein contains two histidine motifs resembling those of metalloproteins such as fatty acid desaturases. FAD4 is targeted to the plastid. Overexpression of the cDNA in transgenic Arabidopsis led to increased accumulation of the Delta(3-trans) hexadecanoyl group in phosphatidylglycerol relative to wild type. Taken together these results are consistent with the hypothesis that FAD4 is the founding member of a novel class of fatty acid desaturases.

  9. [Affective syndromes in liver transplant recipients: ¿mediated neurotoxicity immunosuppressive?].

    PubMed

    Restrepo, Diana Patricia; Tamayo, Alejandra

    2015-01-01

    The onset of affective and psychotic in liver transplant patients symptoms, raises the need to explore the possible etiologies of mental symptoms. Case report and literature review. Four clinical cases of patients undergoing orthotopic liver transplantation, who in the early post transplant showed affective symptoms, delusions and psychomotor agitation for which they needed psychiatric hospitalization and treatment with psychotropic drugs are presented. Three of the patients had clinical improvement and one patient died by suicide. The development of mental symptoms in the post-transplant period opens the possibility of considering the secondary organic mental disorder a basic condition. The adverse drug reaction may explain affective mental disorders in these four cases were reported. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  10. Methoxychlor affects multiple hormone signaling pathways in the largemouth bass (Micropterus salmoides) liver

    PubMed Central

    Martyniuk, Christopher J.; Spade, Daniel J.; Blum, Jason L.; Kroll, Kevin J.; Denslow, Nancy D.

    2011-01-01

    Methoxychlor (MXC) is an organochlorine pesticide that has been shown to have estrogenic activity by activating estrogen receptors and inducing vitellogenin production in male fish. Previous studies report that exposure to MXC induces changes in mRNA abundance of reproductive genes in the liver and testes of largemouth bass (Micropterus salmoides). The objective of the present study was to better characterize the mode of action of MXC by measuring the global transcriptomic response in the male largemouth liver using an oligonucleotide microarray. Microarray analysis identified highly significant changes in the expression of 37 transcripts (p<0.001) (20 induced and 17 decreased) in the liver after MXC injection and a total of 900 expression changes (p<0.05) in transcripts with high homology to known genes. Largemouth bass estrogen receptor alpha (esr1) and androgen receptor (ar) were among the transcripts that were increased in the liver after MXC treatment. Functional enrichment analysis identified the molecular functions of steroid binding and androgen receptor activity as well as steroid hormone receptor activity as being significantly over-represented gene ontology terms. Pathway analysis identified c-fos signaling as being putatively affected through both estrogen and androgen signaling. This study provides evidence that MXC elicits transcriptional effects through the estrogen receptor as well as androgen receptor-mediated pathways in the liver. PMID:21276474

  11. Analysis of the Liver Soluble Proteome from Bull Terriers Affected with Inherited Lethal Acrodermatitis

    PubMed Central

    Mouat, Michael F.; Mauldin, Elizabeth A.; Casal, Margret L.

    2012-01-01

    Lethal acrodermatitis (LAD) is a genetic disease affecting bull terrier dogs. The phenotype is similar to that for acrodermatitis enteropathica in humans, but is currently without treatment. The purpose of the research presented here is to determine the biochemical defects associated with LAD using proteomic methodologies. Two affected (male and female) and one unaffected (male) bull terrier pups were euthanized at 14 weeks of age, their livers dissected and prepared for two-dimensional gel electrophoresis (2DE) and densitometry. Approximately 200 protein spots were observed. The density of the spots within each gel was normalized to the total spot volume of the gel; only those soluble liver protein spots that were consistently different in both of the livers of the affected pups compared to the unaffected pup were excised manually and submitted for MALDI mass spectrometry. Thirteen proteins were identified as differentially expressed in the affected, compared to the unaffected, pups. The proteins were involved in numerous cellular physiological functions, including chaperones, calcium binding, and energy metabolism, as well as being associated with the inflammatory response. Of note were haptoglobin, glutamine synthetase, prohibitin and keratin 10 which exhibited at least a 4-fold level of differential expression. These data represent the first proteomic analysis of this mutation. The differentially expressed proteins that were identified may be key in understanding the etiology of LAD, and may lead to diagnostic tools for its identification within the bull terrier population. PMID:17693109

  12. Changes in Liver Cell DNA Methylation Status in Diabetic Mice Affect Its FT-IR Characteristics

    PubMed Central

    Vidal, Benedicto de Campos; Ghiraldini, Flávia Gerelli; Mello, Maria Luiza S.

    2014-01-01

    Background Lower levels of cytosine methylation have been found in the liver cell DNA from non-obese diabetic (NOD) mice under hyperglycemic conditions. Because the Fourier transform-infrared (FT-IR) profiles of dry DNA samples are differently affected by DNA base composition, single-stranded form and histone binding, it is expected that the methylation status in the DNA could also affect its FT-IR profile. Methodology/Principal Findings The DNA FT-IR signatures obtained from the liver cell nuclei of hyperglycemic and normoglycemic NOD mice of the same age were compared. Dried DNA samples were examined in an IR microspectroscope equipped with an all-reflecting objective (ARO) and adequate software. Conclusions/Significance Changes in DNA cytosine methylation levels induced by hyperglycemia in mouse liver cells produced changes in the respective DNA FT-IR profiles, revealing modifications to the vibrational intensities and frequencies of several chemical markers, including νas –CH3 stretching vibrations in the 5-methylcytosine methyl group. A smaller band area reflecting lower energy absorbed in the DNA was found in the hyperglycemic mice and assumed to be related to the lower levels of –CH3 groups. Other spectral differences were found at 1700–1500 cm−1 and in the fingerprint region, and a slight change in the DNA conformation at the lower DNA methylation levels was suggested for the hyperglycemic mice. The changes that affect cytosine methylation levels certainly affect the DNA-protein interactions and, consequently, gene expression in liver cells from the hyperglycemic NOD mice. PMID:25019512

  13. Alpha linolenic acid in maternal diet halts the lipid disarray due to saturated fatty acids in the liver of mice offspring at weaning.

    PubMed

    Shomonov-Wagner, Limor; Raz, Amiram; Leikin-Frenkel, Alicia

    2015-02-26

    Alpha linolenic acid (ALA, 18:3) in maternal diets has been shown to attenuate obesity associated insulin resistance (IR) in adult offspring in mice. The objective in the present study was to detect the early effects of maternal dietary saturated fatty acids (SFA) and their partial substitution with ω-3 ALA, docosa hexenoic acid (DHA,22:6) and eicosapentenoic acid 20:5 (EPA,20:5) on the HOMA index, liver lipids and fatty acid desaturases in the offspring at weaning. 3 month old C57Bl6/J female mice were fed diets containing normal amount of calories but rich in SFA alone or partially replaced with ALA, DHA or EPA before mating, during pregnancy and lactation. Pregnant mice fed SFA produced offspring with the highest HOMA index, liver lipids and desaturase activities. ALA prevented SFA induced lipid increase but DHA and EPA only reduced it by 42% and 31% respectively. ALA, DHA and EPA decreased HOMA index by 84%, 75% and 83% respectively. ALA, DHA and EPA decreased Δ6 and SCD1 desaturase activities about 30%. SFA feeding to mothers predisposes their offspring to develop IR and liver lipid accumulation already at weaning. ω3 fatty acids reduce IR, ALA halts lipid accumulation whereas DHA and EPA only blunt it.ALA and DHA restore the increased SCD1 to normal. These studies suggest that ω-3 fatty acids have different potencies to preclude lipid accumulation in the offspring partially by affecting pathways associated to SCD1 modulation.

  14. Bleaching Herbicide Flurtamone Interferes with Phytoene Desaturase

    PubMed Central

    Sandmann, Gerhard; Ward, Carl E.; Lo, William C.; Nagy, Jon O.; Böger, Peter

    1990-01-01

    The mode of action of the furanone herbicide flurtamone and derivatives was investigated with cress seedlings and with the unicellular cyanobacterium Anacystis. Either in the light or in the dark these compounds inhibited the formation of α- and β-carotene and all of the xanthophylls in the seedlings. Instead, phytoene, a precursor of colored carotenoids, was accumulated. In illuminated seedlings photooxidative destruction of chlorophyll was observed. The I50 value of flurtamone inhibition of carotenoid biosynthesis in intact Anacystis cells and the K1 value for interaction of flurtamone with phytoene desaturase with Anacystis thylakoids were 30 and 18 nanomoles, respectively. Concentrations of flurtamone which strongly inhibited carotenoid synthesis had no direct peroxidative activities and did not inhibit photosynthetic electron transport. PMID:16667736

  15. 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

  16. Wilson disease: changes in methionine metabolism and inflammation affect global DNA methylation in early liver disease

    PubMed Central

    Medici, Valentina; Shibata, Noreene M.; Kharbanda, Kusum K.; LaSalle, Janine M.; Woods, Rima; Liu, Sarah; Engelberg, Jesse A.; Devaraj, Sridevi; Török, Natalie J.; Jiang, Joy X.; Havel, Peter J.; Lönnerdal, Bo; Kim, Kyoungmi; Halsted, Charles H.

    2012-01-01

    Hepatic methionine metabolism may play an essential role in regulating methylation status and liver injury in Wilson disease (WD) through the inhibition of S-adenosylhomocysteine hydrolase (SAHH) by copper (Cu) and the consequent accumulation of S-adenosylhomocysteine (SAH). We studied the transcript levels of selected genes related to liver injury, levels of SAHH, SAH, DNA methyltransferases genes (Dnmt1, Dnmt3a, Dnmt3b) and global DNA methylation in the tx-j mouse (tx-j), an animal model of WD. Findings were compared to those in control C3H mice, and in response to Cu chelation by penicillamine (PCA) and dietary supplementation of the methyl donor betaine to modulate inflammatory and methylation status. Transcript levels of selected genes related to endoplasmic reticulum stress, lipid synthesis, and fatty acid oxidation were down-regulated at baseline in tx-j mice, further down-regulated in response to PCA, and showed little to no response to betaine. Hepatic Sahh transcript and protein levels were reduced in tx-j mice with consequent increase of SAH levels. Hepatic Cu accumulation was associated with inflammation, as indicated by histopathology and elevated serum ALT and liver tumor necrosis factor alpha (Tnf-α) levels. Dnmt3b was down-regulated in tx-j mice together with global DNA hypomethylation. PCA treatment of tx-j mice reduced Tnf-α and ALT levels, betaine treatment increased S-adenosylmethionine and up-regulated Dnmt3b levels, and both treatments restored global DNA methylation levels. Conclusion: reduced hepatic Sahh expression was associated with increased liver SAH levels in the tx-j model of WD, with consequent global DNA hypomethylation. Increased global DNA methylation was achieved by reducing inflammation by Cu chelation or by providing methyl groups. We propose that increased SAH levels and inflammation affect widespread epigenetic regulation of gene expression in WD. PMID:22945834

  17. The Bacillus subtilis Acyl Lipid Desaturase Is a Δ5 Desaturase

    PubMed Central

    Altabe, Silvia G.; Aguilar, Pablo; Caballero, Gerardo M.; de Mendoza, Diego

    2003-01-01

    Bacillus subtilis was recently reported to synthesize unsaturated fatty acids (UFAs) with a double bond at positions Δ5, Δ7, and Δ9 (M. H. Weber, W. Klein, L. Muller, U. M. Niess, and M. A. Marahiel, Mol. Microbiol. 39:1321-1329, 2001). Since this finding would have considerable importance in the double-bond positional specificity displayed by the B. subtilis acyl lipid desaturase, we have attempted to confirm this observation. We report that the double bond of UFAs synthesized by B. subtilis is located exclusively at the Δ5 position, regardless of the growth temperature and the length chain of the fatty acids. PMID:12730185

  18. Liver cirrhosis in Fontan patients does not affect 1-year post-heart transplant mortality or markers of liver function.

    PubMed

    Simpson, Kathleen E; Esmaeeli, Amir; Khanna, Geetika; White, Francis; Turnmelle, Yumirle; Eghtesady, Pirooz; Boston, Umar; Canter, Charles E

    2014-02-01

    Liver cirrhosis is recognized with long-term follow-up of patients after the Fontan procedure. The effect of liver cirrhosis on the use of heart transplant (HT) and on post-HT outcomes is unknown. We reviewed Fontan patients evaluated for HT from 2004 to 2012 with hepatic computed tomography (CT) imaging, classified as normal, non-cirrhotic changes, or cirrhosis. The primary outcome was 1-year all-cause mortality, and the secondary outcome was differences in serial post-HT liver evaluation. CT imaging in 32 Fontan patients evaluated for HT revealed 20 (63%) with evidence of liver disease, including 13 (41%) with cirrhosis. Twenty underwent HT, including 5 non-cirrhotic and 7 cirrhosis patients. Characteristics at listing between normal or non-cirrhotic (n = 13) and cirrhosis (n = 7) groups were similar, except cirrhosis patients were older (median 17.6 vs 9.6 years, p = 0.002) and further from Fontan (median 180 vs 50 months, p < 0.05). Serial liver evaluation was similar, including aspartate aminotransferase, alanine aminotransferase, bilirubin, albumin, and tacrolimus dose at 1, 3, 6, 9, and 12 months. Overall patient survival was 80% at 1 year, with no difference between cirrhosis and non-cirrhosis patients (86% vs 77%, p = 0.681). Liver biopsies were performed in 7 patients before HT, and all specimens showed architectural changes with bridging fibrosis. Most patients evaluated for HT had abnormal liver findings by CT, with cirrhosis in 41%. One-year mortality and serial liver evaluation were similar between groups after HT. Liver cirrhosis identified by CT imaging may not be an absolute contraindication to HT alone in this population. © 2014 International Society for Heart and Lung Transplantation Published by International Society for the Heart and Lung Transplantation All rights reserved.

  19. Factors affecting surgical margin recurrence after hepatectomy for colorectal liver metastases

    PubMed Central

    Akyuz, Muhammet; Aucejo, Federico; Quintini, Cristiano; Miller, Charles; Fung, John

    2016-01-01

    Background Hepatic recurrence after resection of colorectal liver metastasis (CLM) occurs in 50% of patients during follow-up, with 2.8% to 13.9% presenting with surgical margin recurrence (SMR). The aim of this study is to analyze factors that related to SMR in patients with CLM undergoing hepatectomy. Methods Demographics, clinical and survival data of patients who underwent hepatectomy were identified from a prospectively maintained, institutional review board (IRB)-approved database between 2000 and 2012. Statistical analysis was performed using univariate Kaplan Meier and Cox proportional hazard model. Results There were 85 female and 121 male patients who underwent liver resection for CLM. An R0 resection was performed in 157 (76%) patients and R1 resection in 49. SMR was detected in 32 patients (15.5%) followed up for a median of 29 months (range, 3–121 months). A half of these patients had undergone R1 (n=16) and another half R0 resection (n=16). Tumor size, preoperative carcinoembryonic antigen (CEA) level and margin status were associated with SMR on univariate analysis. On multivariate analysis, a positive surgical margin was the only independent predictor of SMR. The receipt of adjuvant chemotherapy did not affect margin recurrence. SMR was an independent risk factor associated with worse disease-free (DFS) and overall survival (OS). Conclusions This study shows that SMR, which can be detected in up to 15.5% of patients after liver resection for CLM, adversely affects DFS and OS. The fact that a positive surgical margin was the only predictive factor for SMR in these patients underscores the importance of achieving negative margins during hepatectomy. PMID:27294032

  20. Factors affecting surgical margin recurrence after hepatectomy for colorectal liver metastases.

    PubMed

    Akyuz, Muhammet; Aucejo, Federico; Quintini, Cristiano; Miller, Charles; Fung, John; Berber, Eren

    2016-06-01

    Hepatic recurrence after resection of colorectal liver metastasis (CLM) occurs in 50% of patients during follow-up, with 2.8% to 13.9% presenting with surgical margin recurrence (SMR). The aim of this study is to analyze factors that related to SMR in patients with CLM undergoing hepatectomy. Demographics, clinical and survival data of patients who underwent hepatectomy were identified from a prospectively maintained, institutional review board (IRB)-approved database between 2000 and 2012. Statistical analysis was performed using univariate Kaplan Meier and Cox proportional hazard model. There were 85 female and 121 male patients who underwent liver resection for CLM. An R0 resection was performed in 157 (76%) patients and R1 resection in 49. SMR was detected in 32 patients (15.5%) followed up for a median of 29 months (range, 3-121 months). A half of these patients had undergone R1 (n=16) and another half R0 resection (n=16). Tumor size, preoperative carcinoembryonic antigen (CEA) level and margin status were associated with SMR on univariate analysis. On multivariate analysis, a positive surgical margin was the only independent predictor of SMR. The receipt of adjuvant chemotherapy did not affect margin recurrence. SMR was an independent risk factor associated with worse disease-free (DFS) and overall survival (OS). This study shows that SMR, which can be detected in up to 15.5% of patients after liver resection for CLM, adversely affects DFS and OS. The fact that a positive surgical margin was the only predictive factor for SMR in these patients underscores the importance of achieving negative margins during hepatectomy.

  1. Listening to the consumer voice: developing multilingual cancer information resources for people affected by liver cancer.

    PubMed

    Robotin, Monica C; Porwal, Mamta; Hopwood, Max; Nguyen, Debbie; Sze, Minglo; Treloar, Carla; George, Jacob

    2017-02-01

    In Australia, liver cancer incidence is rising, particularly among people born in hepatitis B-endemic countries. We sought to build an understanding of the information needs of people affected by liver cancer, to inform the design of in-language consumer information resources. We searched the World Wide Web for available in-language consumer information and conducted a literature search on consumers' information needs and their preferred means of accessing it. Qualitative data collection involved bilingual researchers conducting focus group discussions (26 participants) and in-depth interviews (22 participants) with people affected by liver cancer in English, Vietnamese, Cantonese and Mandarin. Sessions were audio-recorded, transcribed, translated and thematically analysed. The key themes and salient findings informed the development of in-language multimedia information resources. Many consumer resources did not cater for people with low literacy levels. The participants wanted more information on cancer diagnostic and treatment options, nutrition and Chinese Medicine and experienced communication challenges speaking to health professionals. While Vietnamese speakers relied entirely on information provided by their doctors, other participants actively searched for additional treatment information and commonly used the Internet to source it. We developed multilingual, multimedia consumer information resources addressing identified consumer information needs through an iterative process, in collaboration with our multilingual consumer panel. These resources are available in four languages, as separate modules accessible online and in DVD format. This process enabled the development of user-friendly patient resources, which complement health-care provider information and supports informed patient decision making. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

  2. Two Δ6-desaturase-like genes in common carp (Cyprinus carpio var. Jian): structure characterization, mRNA expression, temperature and nutritional regulation.

    PubMed

    Ren, Hong-tao; Zhang, Guang-qin; Li, Jian-lin; Tang, Yong-kai; Li, Hong-xia; Yu, Ju-hua; Xu, Pao

    2013-08-01

    Δ6-Desaturase is the rate-limiting enzyme involved in highly unsaturated fatty acid (HUFA) biosynthesis. There is very little information on the evolution and functional characterization of Δ6Fad-a and Δ6Fad-b in common carp (Cyprinus carpio var. Jian). In the present study, the genomic sequences and structures of two putative Δ6-desaturase-like genes in common carp genome were obtained. We investigated the mRNA expression patterns of Δ6Fad-a and Δ6Fad-b in tissue, hatching carp embryos, larvae by temperature shock and juveniles under nutritional regulation. Our results showed that the two Δ6Fad genes had identical coding exon structures, being comprised of 12 coding exons, and with introns of distinct size and sequence composition. They were not allelic variants of a single gene. Both Δ6Fad genes were highly expressed in liver, intestine (pyloric caeca) and brain. The Δ6Fad-a and Δ6Fad-b mRNAs showed an increase in expression from newly hatched to 25 days after hatching. The expression levels of Δ6Fad-a were obviously regulated by temperature, whereas Δ6Fad-b was not affected by temperature. The regulation of Δ6Fad-a and Δ6Fad-b in response to dietary fatty acid composition was determined in liver, brain and intestine (pyloric caeca) of common carp fed with diets: diet1with fish oil (FO) rich in n-3 HUFA, diet2 with corn oil (CO, 18:2n-6) and diet3 with linseed oil (LO, 18:3n-3). The differential expression of Δ6Fad-a and Δ6Fad-b genes in liver, brain and intestine in common carps was fed with different oil sources, respectively. Further work is in progress to determine the mechanism of differential expression of the Δ6Fad-a and Δ6Fad-b genes in different tissues and the roles of transcription factors in regulating HUFA synthesis. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Stearoyl-CoA Desaturase and its Relation to High-Carbohydrate Diets and Obesity

    PubMed Central

    Flowers, Matthew T.; Ntambi, James M.

    2009-01-01

    Obesity is currently a worldwide epidemic and public health burden that increases the risk for developing insulin resistance and several chronic diseases such as diabetes, cardiovascular diseases and non-alcoholic fatty liver disease. The multifactorial causes of obesity include several genetic, dietary and lifestyle variables that together result in an imbalance between energy intake and energy expenditure. Dietary approaches to limit fat intake are commonly prescribed to achieve the hypocaloric conditions necessary for weight loss. But dietary fat restriction is often accompanied by increased carbohydrate intake, which can dramatically increase endogenous fatty acid synthesis depending upon carbohydrate composition. Since both dietary and endogenously synthesized fatty acids contribute to the whole-body fatty acid pool, obesity can therefore result from excessive fat or carbohydrate consumption. Stearoyl-Coenzyme A desaturase-1 (SCD1) is a delta-9 fatty acid desaturase that converts saturated fatty acids into monounsaturated fatty acids (MUFA) and this activity is elevated by dietary carbohydrate. Mice lacking Scd1 are protected from obesity and insulin resistance and are characterized by decreased fatty acid synthesis and increased fatty acid oxidation. In this review, we address the association of high-carbohydrate diets with increased SCD activity and summarize the current literature on the subject of SCD1 and body weight regulation. PMID:19166967

  4. DEPTOR in POMC neurons affects liver metabolism but is dispensable for the regulation of energy balance.

    PubMed

    Caron, Alexandre; Labbé, Sébastien M; Mouchiroud, Mathilde; Huard, Renaud; Lanfray, Damien; Richard, Denis; Laplante, Mathieu

    2016-06-01

    We have recently demonstrated that specific overexpression of DEP-domain containing mTOR-interacting protein (DEPTOR) in the mediobasal hypothalamus (MBH) protects mice against high-fat diet-induced obesity, revealing DEPTOR as a significant contributor to energy balance regulation. On the basis of evidence that DEPTOR is expressed in the proopiomelanocortin (POMC) neurons of the MBH, the present study aimed to investigate whether these neurons mediate the metabolic effects of DEPTOR. Here, we report that specific DEPTOR overexpression in POMC neurons does not recapitulate any of the phenotypes observed when the protein was overexpressed in the MBH. Unlike the previous model, mice overexpressing DEPTOR only in POMC neurons 1) did not show differences in feeding behavior, 2) did not exhibit changes in locomotion activity and oxygen consumption, 3) did not show an improvement in systemic glucose metabolism, and 4) were not resistant to high-fat diet-induced obesity. These results support the idea that other neuronal populations are responsible for these phenotypes. Nonetheless, we observed a mild elevation in fasting blood glucose, insulin resistance, and alterations in liver glucose and lipid homeostasis in mice overexpressing DEPTOR in POMC neurons. Taken together, these results show that DEPTOR overexpression in POMC neurons does not affect energy balance regulation but could modulate metabolism through a brain-liver connection. Copyright © 2016 the American Physiological Society.

  5. Analysis of Common and Specific Mechanisms of Liver Function Affected by Nitrotoluene Compounds

    PubMed Central

    Deng, Youping; Meyer, Sharon A.; Guan, Xin; Escalon, Barbara Lynn; Ai, Junmei; Wilbanks, Mitchell S.; Welti, Ruth; Garcia-Reyero, Natàlia; Perkins, Edward J.

    2011-01-01

    Background Nitrotoluenes are widely used chemical manufacturing and munitions applications. This group of chemicals has been shown to cause a range of effects from anemia and hypercholesterolemia to testicular atrophy. We have examined the molecular and functional effects of five different, but structurally related, nitrotoluenes on using an integrative systems biology approach to gain insight into common and disparate mechanisms underlying effects caused by these chemicals. Methodology/Principal Findings Sprague-Dawley female rats were exposed via gavage to one of five concentrations of one of five nitrotoluenes [2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2ADNT) 4-amino-2,6-dinitrotoulene (4ADNT), 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT)] with necropsy and tissue collection at 24 or 48 h. Gene expression profile results correlated well with clinical data and liver histopathology that lead to the concept that hematotoxicity was followed by hepatotoxicity. Overall, 2,4DNT, 2,6DNT and TNT had stronger effects than 2ADNT and 4ADNT. Common functional terms, gene expression patterns, pathways and networks were regulated across all nitrotoluenes. These pathways included NRF2-mediated oxidative stress response, aryl hydrocarbon receptor signaling, LPS/IL-1 mediated inhibition of RXR function, xenobiotic metabolism signaling and metabolism of xenobiotics by cytochrome P450. One biological process common to all compounds, lipid metabolism, was found to be impacted both at the transcriptional and lipid production level. Conclusions/Significance A systems biology strategy was used to identify biochemical pathways affected by five nitroaromatic compounds and to integrate data that tie biochemical alterations to pathological changes. An integrative graphical network model was constructed by combining genomic, gene pathway, lipidomic, and physiological endpoint results to better understand mechanisms of liver toxicity and physiological endpoints

  6. 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.

  7. Liver fungal infections: an overview of the etiology and epidemiology in patients affected or not affected by oncohematologic malignancies

    PubMed Central

    Bimonte, Sabrina; Maraolo, Alberto Enrico; Gentile, Ivan; Schiavone, Vincenzo; Pace, Maria Caterina

    2018-01-01

    Fungal infections of the liver, most commonly caused by Candida spp., often occur in patients with hematologic malignancies treated with chemotherapy. Colonization of the gastrointestinal tract is thought to be the main origin of dissemination of Candida; mucositis and neutropenia facilitate the spread of Candida from the gastrointestinal tract to the liver. Hepatic involvement due to other fungi is a less common infectious complication in this setting. Fungal infections represent a less common cause of hepatic abscesses in non-oncohematologic population and the trend appears to be decreasing in recent years. Understanding of the etiology and epidemiology of fungal infections of the liver is indicated for an appropriate antimicrobial therapy and an overall optimal management of fungal liver infections. PMID:29416363

  8. Early nutritional programming affects liver transcriptome in diploid and triploid Atlantic salmon, Salmo salar.

    PubMed

    Vera, L M; Metochis, C; Taylor, J F; Clarkson, M; Skjærven, K H; Migaud, H; Tocher, D R

    2017-11-17

    To ensure sustainability of aquaculture, plant-based ingredients are being used in feeds to replace marine-derived products. However, plants contain secondary metabolites which can affect food intake and nutrient utilisation of fish. The application of nutritional stimuli during early development can induce long-term changes in animal physiology. Recently, we successfully used this approach to improve the utilisation of plant-based diets in diploid and triploid Atlantic salmon. In the present study we explored the molecular mechanisms occurring in the liver of salmon when challenged with a plant-based diet in order to determine the metabolic processes affected, and the effect of ploidy. Microarray analysis revealed that nutritional history had a major impact on the expression of genes. Key pathways of intermediary metabolism were up-regulated, including oxidative phosphorylation, pyruvate metabolism, TCA cycle, glycolysis and fatty acid metabolism. Other differentially expressed pathways affected by diet included protein processing in endoplasmic reticulum, RNA transport, endocytosis and purine metabolism. The interaction between diet and ploidy also had an effect on the hepatic transcriptome of salmon. The biological pathways with the highest number of genes affected by this interaction were related to gene transcription and translation, and cell processes such as proliferation, differentiation, communication and membrane trafficking. The present study revealed that nutritional programming induced changes in a large number of metabolic processes in Atlantic salmon, which may be associated with the improved fish performance and nutrient utilisation demonstrated previously. In addition, differences between diploid and triploid salmon were found, supporting recent data that indicate nutritional requirements of triploid salmon may differ from those of their diploid counterparts.

  9. Modulation of O-GlcNAc Levels in the Liver Impacts Acetaminophen-Induced Liver Injury by Affecting Protein Adduct Formation and Glutathione Synthesis.

    PubMed

    McGreal, Steven R; Bhushan, Bharat; Walesky, Chad; McGill, Mitchell R; Lebofsky, Margitta; Kandel, Sylvie E; Winefield, Robert D; Jaeschke, Hartmut; Zachara, Natasha E; Zhang, Zhen; Tan, Ee Phie; Slawson, Chad; Apte, Udayan

    2018-04-01

    Overdose of acetaminophen (APAP) results in acute liver failure. We have investigated the role of a posttranslational modification of proteins called O-GlcNAcylation, where the O-GlcNAc transferase (OGT) adds and O-GlcNAcase (OGA) removes a single β-D-N-acetylglucosamine (O-GlcNAc) moiety, in the pathogenesis of APAP-induced liver injury. Hepatocyte-specific OGT knockout mice (OGT KO), which have reduced O-GlcNAcylation, and wild-type (WT) controls were treated with 300 mg/kg APAP and the development of injury was studied over a time course from 0 to 24 h. OGT KO mice developed significantly lower liver injury as compared with WT mice. Hepatic CYP2E1 activity and glutathione (GSH) depletion following APAP treatment were not different between WT and OGT KO mice. However, replenishment of GSH and induction of GSH biosynthesis genes were significantly faster in the OGT KO mice. Next, male C57BL/6 J mice were treated Thiamet-G (TMG), a specific inhibitor of OGA to induce O-GlcNAcylation, 1.5 h after APAP administration and the development of liver injury was studied over a time course of 0-24 h. TMG-treated mice exhibited significantly higher APAP-induced liver injury. Treatment with TMG did not affect hepatic CYP2E1 levels, GSH depletion, APAP-protein adducts, and APAP-induced mitochondrial damage. However, GSH replenishment and GSH biosynthesis genes were lower in TMG-treated mice after APAP overdose. Taken together, these data indicate that induction in cellular O-GlcNAcylation exacerbates APAP-induced liver injury via dysregulation of hepatic GSH replenishment response.

  10. Circadian and feeding rhythms differentially affect rhythmic mRNA transcription and translation in mouse liver

    PubMed Central

    Atger, Florian; Gobet, Cédric; Marquis, Julien; Martin, Eva; Wang, Jingkui; Weger, Benjamin; Lefebvre, Grégory; Descombes, Patrick; Naef, Felix; Gachon, Frédéric

    2015-01-01

    Diurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. Although rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light–dark conditions and ad libitum or night-restricted feeding in WT and brain and muscle Arnt-like 1 (Bmal1)-deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic gene expression, Bmal1 deletion affecting surprisingly both transcriptional and posttranscriptional levels. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5′-Terminal Oligo Pyrimidine tract (5′-TOP) sequences and for genes involved in mitochondrial activity, many harboring a Translation Initiator of Short 5′-UTR (TISU) motif. The increased translation efficiency of 5′-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion also affects amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation. PMID:26554015

  11. Dietary fish oil replacement by linseed oil: Effect on growth, nutrient utilization, tissue fatty acid composition and desaturase gene expression in silver barb (Puntius gonionotus) fingerlings.

    PubMed

    Nayak, Madhusmita; Saha, Ashis; Pradhan, Avinash; Samanta, Mrinal; Giri, Shiba Shankar

    2017-03-01

    Silver barb (Puntius gonionotus) is considered a promising medium carp species for freshwater aquaculture in Asia. This study in silver barb was carried out to evaluate the effects of total or partial substitution of dietary fish oil (FO) with linseed oil (LO) on growth, nutrient utilization, whole-body composition, muscle and liver fatty acid composition. Fish (12.1±0.4g of initial body weight) were fed for 60days with five experimental iso-proteinous, iso-lipidic and iso-caloric diets in which FO (control diet) was replaced by 33.3%, 50%, 66.7% and 100% LO. Final weight, weight gain, percent weight gain, SGR decreased linearly (p<0.001) with increasing LO levels in the diets. Dietary LO substitution levels did not significantly (p>0.05) affect the feed conversion ratio (FCR), protein efficiency ratio (PER) and whole body proximate composition. Furthermore, enhanced level of LO increased α-linolenic acid (ALA; 18:3n3) and linoleic acid (LA; 18:2n6) and decreased eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n3) in muscle and liver. To understand the molecular mechanism of long chain-polyunsaturated fatty acid (LC-PUFA) biosynthesis, we cloned and characterized the fatty acyl Δ6 desaturase (Δ6 fad) cDNA and investigated its expression in various organs/tissues following replacement of FO with LO in the diet. The full-length Δ6 fad cDNA was 2056bp encoding 444 amino acids and was widely expressed in various organs/tissues. Replacement of FO with LO increased the expression of Δ6 fad mRNA in liver, muscle and intestine but no significant difference was found in the brain. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. StearoylCoA Desaturase-5: A Novel Regulator of Neuronal Cell Proliferation and Differentiation

    PubMed Central

    Sinner, Debora I.; Kim, Gretchun J.; Henderson, Gregory C.; Igal, R. Ariel

    2012-01-01

    Recent studies have demonstrated that human stearoylCoA desaturase-1 (SCD1), a Δ9-desaturase that converts saturated fatty acids (SFA) into monounsaturated fatty acids, controls the rate of lipogenesis, cell proliferation and tumorigenic capacity in cancer cells. However, the biological function of stearoylCoA desaturase-5 (SCD5), a second isoform of human SCD that is highly expressed in brain, as well as its potential role in human disease, remains unknown. In this study we report that the constitutive overexpression of human SCD5 in mouse Neuro2a cells, a widely used cell model of neuronal growth and differentiation, displayed a greater n-7 MUFA-to-SFA ratio in cell lipids compared to empty-vector transfected cells (controls). De novo synthesis of phosphatidylcholine and cholesterolesters was increased whereas phosphatidylethanolamine and triacylglycerol formation was reduced in SCD5-expressing cells with respect to their controls, suggesting a differential use of SCD5 products for lipogenic reactions. We also observed that SCD5 expression markedly accelerated the rate of cell proliferation and suppressed the induction of neurite outgrowth, a typical marker of neuronal differentiation, by retinoic acid indicating that the desaturase plays a key role in the mechanisms of cell division and differentiation. Critical signal transduction pathways that are known to modulate these processes, such epidermal growth factor receptor (EGFR)Akt/ERK and Wnt, were affected by SCD5 expression. Epidermal growth factor-induced phosphorylation of EGFR, Akt and ERK was markedly blunted in SCD5-expressing cells. Furthermore, the activity of canonical Wnt was reduced whereas the non-canonical Wnt was increased by the presence of SCD5 activity. Finally, SCD5 expression increased the secretion of recombinant Wnt5a, a non-canonical Wnt, whereas it reduced the cellular and secreted levels of canonical Wnt7b. Our data suggest that, by a coordinated modulation of key lipogenic pathways and

  13. Procyanidins Negatively Affect the Activity of the Phosphatases of Regenerating Liver

    PubMed Central

    Stadlbauer, Sven; Rios, Pablo; Ohmori, Ken; Suzuki, Keisuke; Köhn, Maja

    2015-01-01

    Natural polyphenols like oligomeric catechins (procyanidins) derived from green tea and herbal medicines are interesting compounds for pharmaceutical research due to their ability to protect against carcinogenesis in animal models. It is nevertheless still unclear how intracellular pathways are modulated by polyphenols. Monomeric polyphenols were shown to affect the activity of some protein phosphatases (PPs). The three phosphatases of regenerating liver (PRLs) are close relatives and promising therapeutic targets in cancer. In the present study we show that several procyanidins inhibit the activity of all three members of the PRL family in the low micromolar range, whereas monomeric epicatechins show weak inhibitory activity. Increasing the number of catechin units in procyanidins to more than three does not further enhance the potency. Remarkably, the tested procyanidins showed selectivity in vitro when compared to other PPs, and over 10-fold selectivity toward PRL-1 over PRL-2 and PRL-3. As PRL overexpression induces cell migration compared to control cells, the effect of procyanidins on this phenotype was studied. Treatment with procyanidin C2 led to a decrease in cell migration of PRL-1- and PRL-3-overexpressing cells, suggesting the compound-dependent inhibition of PRL-promoted cell migration. Treatment with procyanidin B3 led to selective suppression of PRL-1 overexpressing cells, thereby corroborating the selectivity toward PRL-1- over PRL-3 in vitro. Together, our results show that procyanidins negatively affect PRL activity, suggesting that PRLs could be targets in the polypharmacology of natural polyphenols. Furthermore, they are interesting candidates for the development of PRL-1 inhibitors due to their low cellular toxicity and the selectivity within the PRL family. PMID:26226290

  14. The Identification of Novel Protein-Protein Interactions in Liver that Affect Glucagon Receptor Activity

    PubMed Central

    Froese, Sean; Dai, Feihan F.; Robitaille, Mélanie; Bhattacharjee, Alpana; Huang, Xinyi; Jia, Weiping; Angers, Stéphane; Wheeler, Michael B.; Wei, Li

    2015-01-01

    Glucagon regulates glucose homeostasis by controlling glycogenolysis and gluconeogenesis in the liver. Exaggerated and dysregulated glucagon secretion can exacerbate hyperglycemia contributing to type 2 diabetes (T2D). Thus, it is important to understand how glucagon receptor (GCGR) activity and signaling is controlled in hepatocytes. To better understand this, we sought to identify proteins that interact with the GCGR to affect ligand-dependent receptor activation. A Flag-tagged human GCGR was recombinantly expressed in Chinese hamster ovary (CHO) cells, and GCGR complexes were isolated by affinity purification (AP). Complexes were then analyzed by mass spectrometry (MS), and protein-GCGR interactions were validated by co-immunoprecipitation (Co-IP) and Western blot. This was followed by studies in primary hepatocytes to assess the effects of each interactor on glucagon-dependent glucose production and intracellular cAMP accumulation, and then in immortalized CHO and liver cell lines to further examine cell signaling. Thirty-three unique interactors were identified from the AP-MS screening of GCGR expressing CHO cells in both glucagon liganded and unliganded states. These studies revealed a particularly robust interaction between GCGR and 5 proteins, further validated by Co-IP, Western blot and qPCR. Overexpression of selected interactors in mouse hepatocytes indicated that two interactors, LDLR and TMED2, significantly enhanced glucagon-stimulated glucose production, while YWHAB inhibited glucose production. This was mirrored with glucagon-stimulated cAMP production, with LDLR and TMED2 enhancing and YWHAB inhibiting cAMP accumulation. To further link these interactors to glucose production, key gluconeogenic genes were assessed. Both LDLR and TMED2 stimulated while YWHAB inhibited PEPCK and G6Pase gene expression. In the present study, we have probed the GCGR interactome and found three novel GCGR interactors that control glucagon-stimulated glucose production

  15. ω3 fatty acid desaturases from microorganisms: structure, function, evolution, and biotechnological use.

    PubMed

    Wang, Mingxuan; Chen, Haiqin; Gu, Zhennan; Zhang, Hao; Chen, Wei; Chen, Yong Q

    2013-12-01

    The biosynthesis of very-long-chain polyunsaturated fatty acids involves an alternating process of fatty acid desaturation and elongation catalyzed by complex series of enzymes. ω3 desaturase plays an important role in converting ω6 fatty acids into ω3 fatty acids. Genes for this desaturase have been identified and characterized in a wide range of microorganisms, including cyanobacteria, yeasts, molds, and microalgae. Like all fatty acid desaturases, ω3 desaturase is structurally characterized by the presence of three highly conserved histidine-rich motifs; however, unlike some desaturases, it lacks a cytochrome b5-like domain. Understanding the structure, function, and evolution of ω3 desaturases, particularly their substrate specificities in the biosynthesis of very-long-chain polyunsaturated fatty acids, lays the foundation for potential production of various ω3 fatty acids in transgenic microorganisms.

  16. The egasyn gene affects the processing of oligosaccharides of lysosomal beta-glucuronidase in liver.

    PubMed Central

    Swank, R T; Pfister, K; Miller, D; Chapman, V

    1986-01-01

    The accumulation of the relatively large amounts of beta-glucuronidase in microsomal fractions of normal mice depends on formation of complexes with the protein egasyn. Unexpectedly, it was found that the egasyn gene also affects the processing of beta-glucuronidase, which is segregated to lysosomes. In egasyn-positive mice lysosomal beta-glucuronidase from liver has a mean pI of 5.9 with a minor proportion at pI 5.4, whereas in egasyn-negative mice the proportion of the two lysosomal forms is reversed. Combined experiments measuring susceptibility to neuraminidase and to endoglycosidase H and specific binding to Ricinus communis lectin-agarose columns showed that the alterations in isoelectric point were associated with a decrease in complex oligosaccharides of lysosomal beta-glucuronidase in egasyn-positive mice. Since this alteration occurs not only in a congenic strain carrying the Eg0 gene but also in several other inbred strains that are homozygous for this gene, it is considered to be a genuine effect of the Eg gene rather than other genes that might regulate oligosaccharide processing. Also, the alteration is likely to be a result of direct physical interaction of the egasyn protein and lysosomal beta-glucuronidase, since a second lysosomal enzyme, beta-galactosidase, which does not form complexes with egasyn, is unaffected. The results suggest a model in which egasyn not only causes accumulation of beta-glucuronidase in the microsomal compartment but also acts upon the precursor to lysosomal beta-glucuronidase to alter its interaction with trans-Golgi-apparatus processing enzymes. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 7. Fig. 8. PMID:3101673

  17. microRNA 21-mediated suppression of Sprouty1 by Pokemon affects liver cancer cell growth and proliferation.

    PubMed

    Jin, Xiu-Li; Sun, Qin-Sheng; Liu, Feng; Yang, Hong-Wei; Liu, Min; Liu, Hong-Xia; Xu, Wei; Jiang, Yu-Yang

    2013-07-01

    Transcriptional repressor Pokemon is a critical factor in embryogenesis, development, cell proliferation, differentiation, and oncogenesis, thus behaving as an oncogene. Oncomine database suggests a potential correlation between the expressions of Pokemon and Sprouty1. This study investigated the regulatory role of Pokemon in Sprouty1 expression and the effect on liver cancer cell growth and proliferation, revealing a novel miR-21-mediated regulatory circuit. In normal (HL-7702) and cancer (QGY-7703) liver cell lines, Sprouty1 expression is inversely correlated with Pokemon levels. Targeted expression or siRNA-mediated silencing showed that Pokemon is a repressor of Sprouty1 expression at both mRNA and protein levels, but Pokemon cannot affect the promoter activity of Sprouty1. Sprouty1 is a target of miR-21 and interestingly, we found that miR-21 is up-regulated by Pokemon in liver cancer cells. Luciferase reporter assays showed that Pokemon up-regulated miR-21 transcription in a dose-dependent manner, and ChIP assay exhibited a direct binding of Pokemon to the miR-21 promoter at -747 to -399 bp. Site-directed mutagenesis of the GC boxes at -684 to -679 bp and -652 to -647 bp of miR-21 promoter abolished the regulatory activity by Pokemon. Furthermore, we found that the modulation of Pokemon and miR-21 expression affected the growth and proliferation of liver cancer cells QGY-7703. In summary, our findings demonstrate that Pokemon suppresses Sprouty1 expression through a miR-21-mediated mechanism, affecting the growth and proliferation of liver cancer cells. This study recognized miR-21 and Sprouty1 as novel targets of the Pokemon regulatory network. Copyright © 2013 Wiley Periodicals, Inc.

  18. Liver condition of Holstein cows affects mitochondrial function and fertilization ability of oocytes.

    PubMed

    Tanaka, Hiroshi; Takeo, Shun; Abe, Takahito; Kin, Airi; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

    2016-06-17

    The aim of the present study was to examine the fertilization ability and mitochondrial function of oocytes derived from cows with or without liver damage. Oocytes were collected from the ovaries of cows with damaged livers (DL) and those of cows with healthy livers (HL), subjected to in vitro maturation, and fertilized in vitro. A significantly high abnormal fertilization rate was observed for oocytes from DL cows compared to oocytes from HL cows. The time to dissolve the zona pellucida by protease before fertilization was similar between the two liver conditions, whereas after fertilization treatment this time was shorter for DL cows than for HL cows. The percentage of oocytes with equivalent cortical granule distributions underneath the membrane was greater for in vitro matured oocytes from HL cows, whereas an immature distribution pattern was observed for oocytes from DL cows. In addition, a greater percentage of oocytes derived from HL cows released cortical granules following fertilization compared with oocytes from DL cows. Mitochondrial function determined by ATP content and membrane potential were similar at the germinal vesicle stage, but post-in vitro maturation, the oocytes derived from HL cows showed higher values than DL cows. The mitochondrial DNA copy number in oocytes was similar between the two liver conditions for both the germinal vesicle and post-in vitro maturation oocytes. In conclusion, liver damage induces low fertilization, likely because of incomplete cortical granule distribution and release, and the maturation of oocytes from DL cows contain low-functioning mitochondria compared to their HL counterparts.

  19. Geographic inequities in liver allograft supply and demand: does it affect patient outcomes?

    PubMed

    Rana, Abbas; Kaplan, Bruce; Riaz, Irbaz B; Porubsky, Marian; Habib, Shahid; Rilo, Horacio; Gruessner, Angelika C; Gruessner, Rainer W G

    2015-03-01

    Significant geographic inequities mar the distribution of liver allografts for transplantation. We analyzed the effect of geographic inequities on patient outcomes. During our study period (January 1 through December 31, 2010), 11,244 adult candidates were listed for liver transplantation: 5,285 adult liver allografts became available, and 5,471 adult recipients underwent transplantation. We obtained population data from the 2010 United States Census. To determine the effect of regional supply and demand disparities on patient outcomes, we performed linear regression and multivariate Cox regression analyses. Our proposed disparity metric, the ratio of listed candidates to liver allografts available varied from 1.3 (region 11) to 3.4 (region 1). When that ratio was used as the explanatory variable, the R(2) values for outcome measures were as follows: 1-year waitlist mortality, 0.23 and 1-year posttransplant survival, 0.27. According to our multivariate analysis, the ratio of listed candidates to liver allografts available had a significant effect on waitlist survival (hazards ratio, 1.21; 95% confidence interval, 1.04-1.40) but was not a significant risk factor for posttransplant survival. We found significant differences in liver allograft supply and demand--but these differences had only a modest effect on patient outcomes. Redistricting and allocation-sharing schemes should seek to equalize regional supply and demand rather than attempting to equalize patient outcomes.

  20. Iron, Oxidative Stress, and Δ9 Stearoyl-CoenzymeA Desaturase Index (C16:1/C16:0): An Analysis Applying the National Health and Nutrition Examination Survey 2003–04

    PubMed Central

    Wu, Yue; Baylin, Ana; Colacino, Justin A

    2018-01-01

    Abstract Background Stearoyl-coenzyme A desaturase (SCD) is a key enzyme in fatty acid metabolism, and elevated SCD activity is associated with multiple adverse health outcomes. Diet, hormone levels, and environmental exposures are potential factors affecting SCD activity. Less is known about the relationship between micronutrients, including iron, and SCD activity. Objective The aim of this study was to investigate the association between serum ferritin level, a biomarker of circulating iron levels, and the Δ9 desaturase index (C16:1/C16:0), a biomarker of estimated SCD activity, among women in the United States. Methods The association between serum ferritin and the Δ9 desaturase index was assessed in a cross-sectional study of 447 female participants, aged 20–49 y, from NHANES 2003–2004. The multivariate analyses were performed utilizing generalized linear modeling, adjusting for potential confounders. Mediation of the relationship between serum ferritin and Δ9 desaturase index by γ-glutamyltranspeptidase (GGT), a biomarker of oxidative stress, was also assessed. Results Increased ferritin was significantly associated with a higher Δ9 desaturase index. Adjusting for waist circumference, age, race, and cotinine levels, an interquartile range increase in serum ferritin corresponded to 3.92% (95% CI: 0.88%, 7.05%) higher Δ9 desaturase index. GGT, the biomarker used to measure oxidative stress level, did not appear to mediate the association between ferritin and Δ9 desaturase index. After stratifying by pregnancy status, these associations were limited to nonpregnant individuals. Conclusions Elevated SCD activity may be associated with increased iron storage inside the human body; the association did not appear to be mediated via oxidative stress, as estimated by GGT levels.

  1. Female Sex But Not Original Indication Affects Physical Activity After Liver Transplant: A Prospective, Single Center Study.

    PubMed

    Kotarska, Katarzyna; Wunsch, Ewa; Raszeja-Wyszomirska, Joanna; Kempińska-Podhorodecka, Agnieszka; Wójcicki, Maciej; Milkiewicz, Piotr

    2015-06-01

    Physical activity has an effect on long-term recovery after major surgical operations including liver transplant. Seven-Day Physical Activity Recall Questionnaire is a semistructured survey that assesses an individual's time spent in physical activity, strength, and flexibility activities during the 7 days prior to the interview. In this study we applied the Seven-Day Physical Activity Recall Questionnaire in patients who underwent liver transplant in our center. We surveyed 107 consecutive patients (62 male and 45 female), who were ≥ 6 months after liver transplant. Patients were divided into 3 groups, depending on time after liver transplant: group A (n = 21), 6 to 12 months posttransplant; group B (n = 48), 13 to 36 months posttransplant; and group C (n = 38), > 37 months posttransplant. Relations were analyzed between physical activity and various factors including sex, age at procedure and survey, time after grafting, original diagnosis, and body mass index. Female patients were significantly less active in daily and weekly measurements (981 ± 212 kcal vs 1267 ± 229 kcal; P < .0001) (6864 ± 1484 kcal vs 8866 ± 1607 kcal; P < .0001). There was a negative correlation between physical activity and age at transplant (P = .02) and survey (P = .02). Neither the time after liver transplant nor the original diagnosis before grafting affected physical activity. Female patients, when assessed with Seven-Day Physical Activity Recall Questionnaire, were significantly less physically active than male subjects after liver transplant. Younger patients were more active, but primary diagnosis had no significant effect on physical activity after grafting.

  2. Relationship between serum TNF activity and insulin resistance in dairy cows affected with naturally occurring fatty liver.

    PubMed

    Ohtsuka, H; Koiwa, M; Hatsugaya, A; Kudo, K; Hoshi, F; Itoh, N; Yokota, H; Okada, H; Kawamura, S

    2001-09-01

    To clarity the relationship between tumor necrosis factor (TNF) and insulin resistance in dairy cows affected with fatty liver, naturally occurring cases were investigated. The affected cows were classified into following three groups according to histopathologic findings of the liver: mild fat droplet deposition (group 1; n=11), severe fat droplet deposition (group 2; n=10), and cloudy swelling (group 3; n=8). Serum TNF activities in Group 2 (8.67 +/- 2.16 U/ml) and Group 3 (11.65 +/- 1.92 U/ml) were significantly higher than that in Group 1 (3.57 +/- 0.81 U/ml) (p<0.05). The insulin-tolerance tests showed that the insulin-stimulated glucose disposal rates (GDR) in Group 2 (27.6 +/- 7.8%) and Group 3 (15.8 +/- 9.1%) were significantly lower than that in Group 1 (41.7 +/- 9.8%). There was a significant negative correlation between serum TNF activity and GDR in affected cows (r=-0.56, p<0.01). These results indicate that serum TNF activity is correlated with insulin resistance in cows with fatty liver.

  3. Primary cilia disruption differentially affects the infiltrating and resident macrophage compartment in the liver.

    PubMed

    Zimmerman, Kurt A; Song, Cheng Jack; Gonzalez-Mize, Nancy; Li, Zhang; Yoder, Bradley K

    2018-06-01

    Hepatorenal fibrocystic disease (HRFCD) is characterized by cysts in the kidney and liver with associated fibrosis and is the result of defects in proteins required for cilia function or assembly. Previous reports indicate that macrophages, mainly M2-like macrophages, contribute to HRFCD, although the origin of these cells (yolk sac-derived resident macrophages vs. bone marrow-derived infiltrating macrophages) and their contribution to the observed phenotypes are unknown. We utilize a congenital model of cilia dysfunction (IFT88 Orpk ) to study the importance of macrophages in HRFCD. Our data show a rapid expansion of the bile duct region and development of fibrosis between 2 and 4 wk of age. Immunofluorescence microscopy analysis reveals an accumulation of F4/80 + macrophages in regions exhibiting biliary hyperplasia in IFT88 Orpk mice. Flow cytometry data show that cilia dysfunction leads to an accumulation of infiltrating macrophages (CD11b hi , F4/80 lo ) and a reduction of resident macrophage (CD11b lo , F4/80 hi ) number. A majority of the infiltrating macrophages are Ly6c hi profibrogenic macrophages. Along with the accumulation of immune cells, expression of proinflammatory and profibrotic transcripts, including TGF-β, TNF-α, IL-1β, and chemokine (C-C) motif ligand 2, is increased. Quantitative RT-PCR analysis of flow-sorted cells shows enhanced expression of CCL2 in cholangiocytes and enhanced expression of VEGF-A and IL-6 in Ly6c hi macrophages. Genetic inhibition of Ly6c hi macrophage accumulation in IFT88 Orpk FVB CCR2 -/- mice reduced biliary fibrosis but did not affect epithelial expansion. Collectively, these studies suggest that biliary epithelium with defects in primary cilia preferentially recruits Ly6c hi infiltrating macrophages, which promote fibrotic progression in HRFCD pathogenesis. NEW & NOTEWORTHY These studies are the first to address the contribution of the infiltrating and resident macrophage niche during progression of hepatorenal

  4. Liver irradiation causes distal bystander effects in the rat brain and affects animal behaviour

    PubMed Central

    Kovalchuk, Anna; Mychasiuk, Richelle; Muhammad, Arif; Hossain, Shakhawat; Ilnytskyy, Slava; Ghose, Abhijit; Kirkby, Charles; Ghasroddashti, Esmaeel; Kovalchuk, Olga; Kolb, Bryan

    2016-01-01

    Radiation therapy can not only produce effects on targeted organs, but can also influence shielded bystander organs, such as the brain in targeted liver irradiation. The brain is sensitive to radiation exposure, and irradiation causes significant neuro-cognitive deficits, including deficits in attention, concentration, memory, and executive and visuospatial functions. The mechanisms of their occurrence are not understood, although they may be related to the bystander effects. We analyzed the induction, mechanisms, and behavioural repercussions of bystander effects in the brain upon liver irradiation in a well-established rat model. Here, we show for the first time that bystander effects occur in the prefrontal cortex and hippocampus regions upon liver irradiation, where they manifest as altered gene expression and somewhat increased levels of γH2AX. We also report that bystander effects in the brain are associated with neuroanatomical and behavioural changes, and are more pronounced in females than in males. PMID:26678032

  5. Liver irradiation causes distal bystander effects in the rat brain and affects animal behaviour.

    PubMed

    Kovalchuk, Anna; Mychasiuk, Richelle; Muhammad, Arif; Hossain, Shakhawat; Ilnytskyy, Slava; Ghose, Abhijit; Kirkby, Charles; Ghasroddashti, Esmaeel; Kovalchuk, Olga; Kolb, Bryan

    2016-01-26

    Radiation therapy can not only produce effects on targeted organs, but can also influence shielded bystander organs, such as the brain in targeted liver irradiation. The brain is sensitive to radiation exposure, and irradiation causes significant neuro-cognitive deficits, including deficits in attention, concentration, memory, and executive and visuospatial functions. The mechanisms of their occurrence are not understood, although they may be related to the bystander effects.We analyzed the induction, mechanisms, and behavioural repercussions of bystander effects in the brain upon liver irradiation in a well-established rat model.Here, we show for the first time that bystander effects occur in the prefrontal cortex and hippocampus regions upon liver irradiation, where they manifest as altered gene expression and somewhat increased levels of γH2AX. We also report that bystander effects in the brain are associated with neuroanatomical and behavioural changes, and are more pronounced in females than in males.

  6. Severity of liver disease affects HCV kinetics in patients treated with intravenous silibinin monotherapy

    DOE PAGES

    Canini, Laetitia; DebRoy, Swati; Mariño, Zoe; ...

    2014-06-10

    HCV kinetic analysis and modeling during antiviral therapy have not been performed in decompensated cirrhotic patients awaiting liver transplantation. Here, viral and host parameters were compared in patients treated with daily intravenous silibinin (SIL) monotherapy for 7 days according to the severity of their liver disease. Data were obtained from 25 patients, 12 non-cirrhotic, 8 with compensated cirrhosis and 5 with decompensated cirrhosis. The standard-biphasic model with time-varying SIL effectiveness (from 0 to ε max) was fit to viral kinetic data. Our results show that baseline viral load and age were significantly associated with the severity of liver disease (p<0.0001).more » A biphasic viral decline was observed in most patients with a higher first phase decline patients with less severe liver disease. The maximal effectiveness, ε max, was significantly (p≤0.032) associated with increasing severity of liver disease (ε max[s.e.]=0.86[0.05], ε max=0.69[0.06] and ε max=0.59[0.1]). The 2nd phase decline slope was not significantly different among groups (mean 1.88±0.15 log 10IU/ml/wk, p=0.75) as was the rate of change of SIL effectiveness (k=2.12/day[standard error, SE=0.18/day]). HCV-infected cell loss rate (δ[SE]=0.62/day[0.05/day]) was high and similar among groups. We conclude that the high loss rate of HCV-infected cells suggests that sufficient dose and duration of SIL might achieve viral suppression in advanced liver disease.« less

  7. Liver condition of Holstein cows affects mitochondrial function and fertilization ability of oocytes

    PubMed Central

    TANAKA, Hiroshi; TAKEO, Shun; ABE, Takahito; KIN, Airi; SHIRASUNA, Koumei; KUWAYAMA, Takehito; IWATA, Hisataka

    2016-01-01

    The aim of the present study was to examine the fertilization ability and mitochondrial function of oocytes derived from cows with or without liver damage. Oocytes were collected from the ovaries of cows with damaged livers (DL) and those of cows with healthy livers (HL), subjected to in vitro maturation, and fertilized in vitro. A significantly high abnormal fertilization rate was observed for oocytes from DL cows compared to oocytes from HL cows. The time to dissolve the zona pellucida by protease before fertilization was similar between the two liver conditions, whereas after fertilization treatment this time was shorter for DL cows than for HL cows. The percentage of oocytes with equivalent cortical granule distributions underneath the membrane was greater for in vitro matured oocytes from HL cows, whereas an immature distribution pattern was observed for oocytes from DL cows. In addition, a greater percentage of oocytes derived from HL cows released cortical granules following fertilization compared with oocytes from DL cows. Mitochondrial function determined by ATP content and membrane potential were similar at the germinal vesicle stage, but post-in vitro maturation, the oocytes derived from HL cows showed higher values than DL cows. The mitochondrial DNA copy number in oocytes was similar between the two liver conditions for both the germinal vesicle and post-in vitro maturation oocytes. In conclusion, liver damage induces low fertilization, likely because of incomplete cortical granule distribution and release, and the maturation of oocytes from DL cows contain low-functioning mitochondria compared to their HL counterparts. PMID:26832309

  8. Discovery of Potent Benzocycloalkane Derived Diapophytoene Desaturase Inhibitors with an Enhanced Safety Profile for the Treatment of MRSA, VISA, and LRSA Infections.

    PubMed

    Li, Baoli; Ni, Shuaishuai; Chen, Feifei; Mao, Fei; Wei, Hanwen; Liu, Yifu; Zhu, Jin; Lan, Lefu; Li, Jian

    2018-03-09

    Blocking the biosynthesis process of staphyloxanthin has emerged as a promising antivirulence strategy. Our previous research revealed that diapophytoene desaturase was an attractive and druggable target against infections caused by pigmented Staphylococcus aureus. Benzocycloalkane-derived compounds were effective inhibitors of diapophytoene desaturase but limited by high hERG (human Ether-a-go-go Related Gene) inhibition activity. Here, we identified a new type of benzo-hepta-containing cycloalkane derivative as diapophytoene desaturase inhibitors. Among the fifty-eight analogues, 48 (hERG inhibition activity, half maximal inhibitory concentration, IC 50 , of 16.1 μM) and 51 (hERG inhibition activity, IC 50 > 40 μM) were distinguished for effectively inhibiting the pigment production of Staphylococcus aureus Newman and three methicillin-resistant Staphylococcus aureus strains, and the four strains were highly sensitize to hydrogen peroxide killing without a bactericidal growth effect. In an in vivo assay, 48 and 51 displayed a comparable effect with linezolid and vancomycin in livers and hearts in mice against Staphylococcus aureus Newman and a more considerable effect against Mu50 and NRS271 with normal administration.

  9. Folate supplementation differently affects uracil content in DNA in the mouse colon and liver

    USDA-ARS?s Scientific Manuscript database

    High folate intake may increase the risk of cancer, especially in the elderly. The present study examined the effects of ageing and dietary folate on uracil misincorporation into DNA, which has a mutagenic effect, in the mouse colon and liver. Old (18 months; n 42) and young (4 months; n 42) male C5...

  10. Vitamin D deficiency is a risk factor for infections in patients affected by HCV-related liver cirrhosis.

    PubMed

    Buonomo, Antonio Riccardo; Zappulo, Emanuela; Scotto, Riccardo; Pinchera, Biagio; Perruolo, Giuseppe; Formisano, Pietro; Borgia, Guglielmo; Gentile, Ivan

    2017-10-01

    To evaluate the prevalence of vitamin D deficiency and its impact on infections in HCV-related liver cirrhosis. We enrolled 291 patients affected by HCV-related liver cirrhosis. Serum vitamin D levels were dosed at enrolment. The presence of infection was assessed at baseline and during follow-up based on physical examination and laboratory analyses. Vitamin D deficiency (<20ng/mL) was diagnosed in 68.3% of patients, and a total of 102 infections were detected. Urinary tract infections were the most common infections diagnosed (41.2%). Vitamin D deficiency rates were higher in patients with decompensated cirrhosis (Child-Pugh B vs A p=0.008, and Child-Pugh C vs A p=0.024). Infection was significantly associated with vitamin D deficiency (p<0.001), MELD score >15 (p=0.003), Child-Pugh class B/C vs A (p<0.001), and active hepatocellular carcinoma (HCC) (p<0.001). At multivariate analysis, vitamin D deficiency (p<0.01), HCC (p<0.05), hospitalization (p<0.001) and exposure to immunosuppressant agents (p<0.05) were independent risk factors for infection at baseline. Vitamin D may play a role in the development of infections in patients affected by liver cirrhosis, and preventive strategies with vitamin D supplementation are to be evaluated in randomized controlled trials. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  11. High dietary intake of sodium selenite does not affect gene mutation frequency in rat colon and liver.

    PubMed

    Zeng, Huawei; Uthus, Eric O; Ross, Sharon A; Davis, Cindy D

    2009-10-01

    Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se. The present study was designed to determine whether dietary selenite affects somatic mutation frequency in vivo. We used the Big Blue transgenic model to evaluate the in vivo mutation frequency of the cII gene in rats fed either a Se-deficient (0 microg Se/g diet) or Se-supplemented diet (0.2 or 2 microg Se/g diet; n = 3 rats/diet in experiment 1 and n = 5 rats/group in experiment 2) and injected with DMH (25 mg/kg body weight, i.p.). There were no significant differences in body weight between the Se-deficient and Se-supplemented (0.2 or 2 microg Se/g diet) rats, but the activities of liver glutathione peroxidase and thioredoxin reductase and concentration of liver Se were significantly lower (p < 0.0001) in Se-deficient rats compared to rats supplemented with Se. We found no effect of dietary Se on liver 8-hydroxy-2'-deoxyguanosine. Gene mutation frequency was significantly lower in liver (p < 0.001) than that of colon regardless of dietary Se. However, there were no differences in gene mutation frequency in DNA from colon mucosa or liver from rats fed the Se-deficient diet compared to those fed the Se-supplemented (0.2 or 2 microg Se/g diet) diet. Although gene mutations have been implicated in the etiology of cancer, our data suggest that decreasing gene mutation is not likely a key mechanism through which dietary selenite exerts its anticancer action against DMH-induced preneoplastic colon cancer lesions in a Big Blue transgenic rat model.

  12. Donor PNPLA3 rs738409 genotype affects fibrosis progression in liver transplantation for hepatitis C.

    PubMed

    Dunn, Winston; O'Neil, Maura; Zhao, Jie; Wu, Chuang Hong; Roberts, Benjamin; Chakraborty, Shweta; Sherman, Craig; Weaver, Brandy; Taylor, Ryan; Olson, Jody; Olyaee, Mojtaba; Gilroy, Richard; Schmitt, Timothy; Wan, Yu-Jui Yvonne; Weinman, Steven A

    2014-02-01

    The rs738409 G>C single nucleotide polymorphism occurring in the patatin-like phospholipase 3 gene has been identified as a novel genetic marker for hepatic steatosis. Recent studies also associated rs738409 with fibrosis in hepatitis C (HCV). Therefore, we sought to determine the impact of donor and recipient rs738409 genotype on the progression of fibrosis after liver transplantation for HCV. This cohort study included 101 patients infected with HCV who underwent liver transplantation between January 2008, and June 2011. Donor and recipient rs738409 genotypes were determined from donor wedge biopsies and recipient explants. The time to Ishak stage 3 fibrosis, or HCV-related mortality/graft loss was analyzed by the Cox model adjusting for HCV-Donor Risk Index, warm ischemic time, pretransplant Model for Endstage Liver Disease (MELD) and viral load. The rs738409 CC variant was present in 56% of donors and 57% of recipients. The median follow-up period was 620 days. A total of 39 patients developed the primary outcome of ≥stage 3 fibrosis or HCV-related mortality/graft loss, the time to which differed by donor (P = 0.019) but not recipient (P = 0.89) genotype. In the multivariate model, donor GC or GG variants had 2.53 times the risk (95% confidence interval [CI] 1.25-5.02, P = 0.008) compared to CC variants. In the alternative endpoint: stage 3 fibrosis or all-cause mortality/graft loss, the effect of donor genotype was attenuated but remained significant at 1.98 (95% CI 1.11-3.53). The rs738409 genotype is an important predictor of posttransplant outcome in HCV. Liver, and not adipocytes, is the site at which this effect occurs. Our finding may be useful in donor selection for liver transplantation with HCV, and may guide decisions regarding early antiviral treatment. © 2013 by the American Association for the Study of Liver Diseases.

  13. Identification of Delta5-fatty acid desaturase from the cellular slime mold dictyostelium discoideum.

    PubMed

    Saito, T; Ochiai, H

    1999-10-01

    cDNA fragments putatively encoding amino acid sequences characteristic of the fatty acid desaturase were obtained using expressed sequence tag (EST) information of the Dictyostelium cDNA project. Using this sequence, we have determined the cDNA sequence and genomic sequence of a desaturase. The cloned cDNA is 1489 nucleotides long and the deduced amino acid sequence comprised 464 amino acid residues containing an N-terminal cytochrome b5 domain. The whole sequence was 38.6% identical to the initially identified Delta5-desaturase of Mortierella alpina. We have confirmed its function as Delta5-desaturase by over expression mutation in D. discoideum and also the gain of function mutation in the yeast Saccharomyces cerevisiae. Analysis of the lipids from transformed D. discoideum and yeast demonstrated the accumulation of Delta5-desaturated products. This is the first report concering fatty acid desaturase in cellular slime molds.

  14. Conversion of hexadecanoic acid to hexadecenoic acid by rat Delta 6-desaturase.

    PubMed

    Guillou, Hervé; Rioux, Vincent; Catheline, Daniel; Thibault, Jean-Nöel; Bouriel, Monique; Jan, Sophie; D'Andrea, Sabine; Legrand, Philippe

    2003-03-01

    A higher content of C16:1 n-10 has recently been reported in the preputial gland of mice with a targeted disruption of the gene encoding stearoyl-CoA desaturase 1 (SCD1-/- mice) when compared with wild-type mice. This result has provided the first physiological evidence for the presence and regulation of a palmitoyl-CoA Delta 6-desaturase in mammals. To investigate the putative involvement of the known Delta 6-desaturase (FADS2) in this process, COS-7 cells expressing rat Delta 6-desaturase were incubated with C16:0. Transfected cells were able to synthesize C16:1 n-10, while nontransfected cells did not produce any C16:1 n-10. Evidence is therefore presented that the rat Delta 6-desaturase, which acts on the 18- and 24-carbon fatty acids of the n-6 and n-3 series, is also able to catalyze palmitic acid Delta 6 -desaturation.

  15. A High Phosphorus Diet Affects Lipid Metabolism in Rat Liver: A DNA Microarray Analysis

    PubMed Central

    Chun, Sunwoo; Bamba, Takeshi; Suyama, Tatsuya; Ishijima, Tomoko; Fukusaki, Eiichiro; Abe, Keiko; Nakai, Yuji

    2016-01-01

    A high phosphorus (HP) diet causes disorders of renal function, bone metabolism, and vascular function. We previously demonstrated that DNA microarray analysis is an appropriate method to comprehensively evaluate the effects of a HP diet on kidney dysfunction such as calcification, fibrillization, and inflammation. We reported that type IIb sodium-dependent phosphate transporter is significantly up-regulated in this context. In the present study, we performed DNA microarray analysis to investigate the effects of a HP diet on the liver, which plays a pivotal role in energy metabolism. DNA microarray analysis was performed with total RNA isolated from the livers of rats fed a control diet (containing 0.3% phosphorus) or a HP diet (containing 1.2% phosphorus). Gene Ontology analysis of differentially expressed genes (DEGs) revealed that the HP diet induced down-regulation of genes involved in hepatic amino acid catabolism and lipogenesis, while genes related to fatty acid β-oxidation process were up-regulated. Although genes related to fatty acid biosynthesis were down-regulated in HP diet-fed rats, genes important for the elongation and desaturation reactions of omega-3 and -6 fatty acids were up-regulated. Concentrations of hepatic arachidonic acid and eicosapentaenoic acid were increased in HP diet-fed rats. These essential fatty acids activate peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor for fatty acid β-oxidation. Evaluation of the upstream regulators of DEGs using Ingenuity Pathway Analysis indicated that PPARα was activated in the livers of HP diet-fed rats. Furthermore, the serum concentration of fibroblast growth factor 21, a hormone secreted from the liver that promotes fatty acid utilization in adipose tissue as a PPARα target gene, was higher (p = 0.054) in HP diet-fed rats than in control diet-fed rats. These data suggest that a HP diet enhances energy expenditure through the utilization of free fatty acids

  16. Intraoperative liver ultrasound still affects surgical strategy for patients with colorectal metastases in the modern era.

    PubMed

    Ferrero, Alessandro; Langella, Serena; Giuliante, Felice; Viganò, Luca; Vellone, Maria; Zimmitti, Giuseppe; Ardito, Francesco; Nuzzo, Gennaro; Capussotti, Lorenzo

    2013-11-01

    The present study was designed to evaluate the role of intraoperative ultrasound (IOUS) in intrahepatic staging and the impact on surgical strategy for patients with colorectal liver metastases (CRLM). The study included 515 patients who had undergone liver resection for CRLM at two tertiary care referral centers. Data from a prospectively collected database were retrospectively analysed. Early intrahepatic recurrence was assessed at 3 and 6 months after resection and was considered as residual disease undetected by IOUS. Performance of imaging modalities was compared by analysis of studies on individual patients. A total of 1,370 liver metastases were detected preoperatively with a median of 3 imaging modalities. MRI and PET were performed in 51 and 42 % of the patients, respectively. Median number of days between last imaging and surgery was 18. Contrast-enhanced IOUS was performed in 136 patients (26.4 %). Intraoperatively, 293 new nodules were found in 132 patients: on histology 280 were CRLM (17.6 %). Surgical strategy was changed in 140 patients (27.2 %). On multivariate analysis synchronous and bilobar metastases ≥ 3 in number, BMI ≥ 30, and time between last imaging and surgery longer than 18 days resulted in predictive factors indicating new nodules detected by IOUS. Early intrahepatic recurrences were 3.7 and 7.9 % at 3 and 6 months. Performance of CT, MRI, FDG-PET, and intraoperative staging was compared: sensitivity was 63.6, 68.8, 53.6, and 92 % and specificity was 91, 92.3, 95.8, and 97.8 %, respectively The use of IOUS continues to be mandatory for correct staging of patients with CRLM undergoing liver resection.

  17. Effects of saturated and unsaturated fatty acids on estimated desaturase activities during a controlled dietary intervention.

    PubMed

    Warensjö, Eva; Risérus, Ulf; Gustafsson, Inga-Britt; Mohsen, Rawya; Cederholm, Tommy; Vessby, Bengt

    2008-12-01

    Direct measurement of desaturase activities are difficult to obtain in humans. Consequently, surrogate measures of desaturase activity (estimated desaturase activities) have been frequently used in observational studies, and estimated Delta(9)- (or stearoyl-CoA-desaturase (SCD)), Delta(6)- and Delta(5)-desaturase activities have been associated with cardiometabolic disease. Data on how the markers of desaturase activities are modified by changes in dietary fat quality are lacking and therefore warrant examination. In a two-period (three weeks) strictly controlled cross-over study, 20 subjects (six women and 14 men) consumed a diet high in saturated fat (SAT-diet) and a rapeseed oil diet (RO-diet), rich in oleic acid (OA), linoleic acid (LA) and alpha-linolenic acid (ALA). Estimated desaturase activities were calculated as precursor to product FA ratios in serum cholesteryl esters and phospholipids. The estimated SCD [16:1 n-7/16:0] and Delta(6)-desaturase [20:3 n-6/18:2 n-6] was significantly higher while Delta(5)-desaturase [20:4 n-6/20:3 n-6] was significantly lower in the SAT-diet (P<0.001 for all), compared to the RO-diet. The serum proportions of palmitic, stearic, palmitoleic and dihomo-gamma-linolenic acids were significantly higher in the SAT-diet while the proportions of LA and ALA were significantly higher in the RO-diet. This is the first study to demonstrate that surrogate measures of desaturase activities change as a consequence of an alteration in dietary fat quality. Both the [16:1/16:0]-ratio and 16:1 seem to reflect changes in saturated fat intake and may be useful markers of saturated fat intake in Western countries.

  18. Functional characterisation of two cytochrome b5-fusion desaturases from Anemone leveillei: the unexpected identification of a fatty acid Delta6-desaturase.

    PubMed

    Whitney, Heather M; Michaelson, Louise V; Sayanova, Olga; Pickett, John A; Napier, Johnathan A

    2003-10-01

    The Ranunculaceae are known to accumulate a wide range of unusual fatty acids in their seed lipids, and this variability has been advocated as a taxonomic marker. The Anemone species, Anemone leveillei L. and Anemone rivularis Buch.-Ham., have previously been reported to accumulate Delta5-desaturated fatty acids in their seed tissue [K. Aitzetmüller (1995) Plant Syst Evol 9:229-240]. Two cDNAs, AL1 and AL2, with similarity to plant cytochrome b5-fusion "front-end" desaturases were isolated from developing seeds of A. leveillei and their function identified by expression in Saccharomyces cerevisiae. AL2 was characterised as a sphingolipid long-chain-base Delta8-desaturase, while AL1 acted as a fatty acid desaturase. However, AL1 did not produce Delta5-desaturated fatty acids as expected; instead, when expressed in transgenic S. cerevisiae or Arabidopsis thaliana this enzyme was functionally characterised as a Delta6-desaturase. Northern analysis confirmed the expression of this gene in seed tissue and leaf tissue of A. leveillei, though Delta6-desaturated fatty acids were found to accumulate only in the leaf tissue. The unexpected characterisation of a Delta6-desaturase in A. leveillei has implications for the use of fatty acids in chemotaxonomic studies. This is also the first report of a higher-plant Delta6-desaturase from a family other than the Boraginaceae.

  19. Hepatitis virus infection affects DNA methylation in mice with humanized livers.

    PubMed

    Okamoto, Yasuyuki; Shinjo, Keiko; Shimizu, Yasuhiro; Sano, Tsuyoshi; Yamao, Kenji; Gao, Wentao; Fujii, Makiko; Osada, Hirotaka; Sekido, Yoshitaka; Murakami, Shuko; Tanaka, Yasuhito; Joh, Takashi; Sato, Shinya; Takahashi, Satoru; Wakita, Takaji; Zhu, Jingde; Issa, Jean-Pierre J; Kondo, Yutaka

    2014-02-01

    Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship. Pyrosequencing was used to determine the methylation status of cultured Huh7.5.1 hepatoma cells after hepatitis C virus (HCV) infection. We also studied mice with severe combined immunodeficiency carrying the urokinase-type plasminogen activator transgene controlled by an albumin promoter (urokinase-type plasminogen activator/severe combined immunodeficient mice), in which up to 85% of hepatocytes were replaced by human hepatocytes (chimeric mice). Mice were given intravenous injections of hepatitis B virus (HBV) or HCV, liver tissues were collected, and DNA methylation profiles were determined at different time points after infection. We also compared methylation patterns between paired samples of hepatocellular carcinomas and adjacent nontumor liver tissues from patients. No reproducible changes in DNA methylation were observed after infection of Huh7.5.1 cells with HCV. Livers from HBV- and HCV-infected mice had genome-wide, time-dependent changes in DNA methylation, compared with uninfected urokinase-type plasminogen activator/severe combined immunodeficient mice. There were changes in 160 ± 63 genes in HBV-infected and 237 ± 110 genes in HCV-infected mice. Methylation of 149 common genes increased in HBV- and HCV-infected mice; methylation of some of these genes also increased in hepatocellular carcinoma samples from patients compared with nontumor tissues. Expression of Ifng, which is expressed by natural killer cells, increased significantly in chimeric livers, in concordance with induction of DNA methylation, after infection with HBV or HCV. Induction of Ifng was reduced after administration of an inhibitor of natural killer cell function (anti-asialo GM1). In chimeric mice with humanized livers

  20. Transient hyperglycemia during liver transplantation does not affect the early graft function.

    PubMed

    Blasi, Annabel; Beltran, Joan; Martin, Nuria; Martinez-Pallí, Graciela; Lozano, Juan J; Balust, Jaume; Torrents, Abigail; Taura, Pilar

    2015-01-01

    Background and rationale for the study. Hyperglycemia after graft reperfusion is a consistent finding in liver transplantation (LT) that remains poorly studied. We aim to describe its appearance in LT recipients of different types of grafts and its relation to the graft function. 436 LT recipients of donors after brain death (DBD), donors after cardiac death (DCD), and familial amyloidotic polyneuropathy (FAP) donors were reviewed. Serum glucose was measured at baseline, during the anhepatic phase, after graft reperfusion, and at the end of surgery. Early graft dysfunction (EAD) was assessed by Olthoff criteria. Caspase-3, IFN-γ, IL1β, and IL6 gene expression were measured in liver biopsy. The highest increase in glucose levels after reperfusion was observed in FAP LT recipients and the lowest in DCD LT recipients. Glucose level during the anhepatic phase was the only modifiable predictive variable of hyperglycemia after reperfusion. No relation was found between hyperglycemia after reperfusion and EAD. However, recipients with the highest glucose levels after reperfusion tended to achieve the best glucose control at the end of surgery and those who were unable to control the glucose value after reperfusion showed EAD more frequently. The highest levels of caspase-3 were found in recipients with the lowest glucose values after reperfusion. In conclusion, glucose levels increased after graft reperfusion to a different extent according to the donor type. Contrary to general belief, transient hyperglycemia after reperfusion does not appear to impact negatively on the liver graft function and could even be suggested as a marker of graft quality.

  1. Polyunsaturated fatty acids balance affects platelet NOX2 activity in patients with liver cirrhosis.

    PubMed

    Basili, Stefania; Raparelli, Valeria; Napoleone, Laura; Del Ben, Maria; Merli, Manuela; Riggio, Oliviero; Nocella, Cristina; Carnevale, Roberto; Pignatelli, Pasquale; Violi, Francesco

    2014-07-01

    NADPH-oxidase-2 up-regulation has been suggested in liver damage perpetuation via an oxidative stress-mediated mechanism. n-6/n-3 polyunsaturated fatty acids ratio derangement has been reported in liver disease. To explore polyunsaturated fatty acids balance and its interplay with platelet oxidative stress in liver cirrhosis. A cross-sectional study in 51 cirrhotic patients and sex- and age-matched controls was performed. Serum polyunsaturated fatty acids and oxidative stress markers (urinary isoprostanes and serum soluble NADPH-oxidase-2-derived peptide) were measured. The effect on platelet oxidative stress of n-6/n-3 polyunsaturated fatty acids ratio in vitro and in vivo (1-week supplementation with 3g/daily n-3-polyunsaturated fatty acids) was tested. Compared to controls, cirrhotic patients had significantly higher n-6/n-3 polyunsaturated fatty acids ratio. n-6/n-3 polyunsaturated fatty acids ratio correlated significantly with disease severity and oxidative stress markers. In vitro experiments showed that in Child-Pugh C patients' platelets incubation with low n-6/n-3 polyunsaturated fatty acids ratio resulted in dose-dependent decrease of radical oxigen species (-39%), isoprostanes (-25%) and NADPH-oxidase-2 regulation (-51%). n-3 polyunsaturated fatty acids supplemented patients showed significant oxidative stress indexes reduction. In cirrhosis, n-6/n-3 polyunsaturated fatty acids imbalance up-regulates platelet NADPH-oxidase-2 with ensuing oxidative stress. Further study to evaluate if n-3 supplementation may reduce disease progression is warranted. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  2. Obesity resistance and deregulation of lipogenesis in Δ6-fatty acid desaturase (FADS2) deficiency.

    PubMed

    Stoffel, Wilhelm; Hammels, Ina; Jenke, Britta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Odenthal, Margarete; Thevis, Mario

    2014-01-01

    Δ-6-fatty acid desaturase (FADS2) is the key enzyme in the biosynthesis of polyunsaturated fatty acids (PUFAs), the essential structural determinants of mammalian membrane lipid-bilayers. We developed the auxotrophic fads2(-/-) mouse mutant to assess the enigmatic role of ω3- and ω6-PUFAs in lipid homeostasis, membrane structure and function. Obesity resistance is another major phenotype of the fads2(-/-) mutant, the molecular basis of which is unknown. Phospholipidomic profiling of membrane systems of fads2(-/-)mice revealed diacylglycerol-structures, deprived of PUFAs but substituted with surrogate eicosa-5,11,14-trienoic acid. ω6-Arachidonic (AA) and ω3-docosahexaenoic acid (DHA) supplemented diets transformed fads2(-/-) into AA-fads2(-/-) and DHA-fads2(-/-) mutants. Severely altered phospholipid-bilayer structures of subcellular membranes of fads2(-/-) liver specifically interfered with maturation of transcription factor sterol-regulatory-element-binding protein, the key regulator of lipogenesis and lipid homeostasis. This study strengthens the concept that specific PUFA-substituted membrane phospholipid species are critical constituents of the structural platform operative in lipid homeostasis in normal and disease conditions.

  3. Dietary vitamin E deficiency does not affect global and specific DNA methylation patterns in rat liver.

    PubMed

    Fischer, Alexandra; Gaedicke, Sonja; Frank, Jan; Döring, Frank; Rimbach, Gerald

    2010-10-01

    The aim of the present study was to determine the effects of a 6-month dietary vitamin E (VE) deficiency on DNA methylation and gene expression in rat liver. Two enzymes, 5-α-steroid reductase type 1 (SRD5A1) and the regulatory subunit of γ-glutamylcysteinyl synthetase (GCLM), which are differentially expressed on the mRNA level, were analysed for promoter methylation in putative cytosine-phospho-guanine (CpG) island regions located at the 5' end using base-specific cleavage and matrix-assisted laser desorption ionisation time-of-flight MS. A twofold increase in the mRNA level of SRD5A1 gene and a twofold decrease in the mRNA level of GCLM gene in VE-deficient animals were not associated with different CpG methylation of the analysed promoter region. Furthermore, global DNA methylation was not significantly different in these two groups. Thus, the present results indicate that the VE-induced regulation of SRD5A1 and GCLM in rat liver is not directly mediated by changes in promoter DNA methylation.

  4. Effect of two intermediate electron donors, NADPH and FADH(2), on Spirulina Delta (6)-desaturase co-expressed with two different immediate electron donors, cytochrome b (5) and ferredoxin, in Escherichia coli.

    PubMed

    Kurdrid, Pavinee; Subudhi, Sanjukta; Cheevadhanarak, Supapon; Tanticharoen, Morakot; Hongsthong, Apiradee

    2007-12-01

    When the gene desD encoding Spirulina Delta(6)-desaturase was heterologously expressed in E. coli, the enzyme was expressed without the ability to function. However, when this enzyme was co-expressed with an immediate electron donor, i.e. the cytochrome b (5) domain from Mucor rouxii, the results showed the production of GLA (gamma-linolenic acid), the product of the reaction catalyzed by Delta(6)-desaturase. The results revealed that in E. coli cells, where cytochrome b (5) is absent and ferredoxin, a natural electron donor of Delta(6)-desaturase, is present at a very low level, the cytochrome b (5) domain can complement for the function of ferredoxin in the host cells. In the present study, the Spirulina-ferredoxin gene was cloned and co-expressed with the Delta(6)-desaturase in E. coli. In comparison to the co-expression of cytochrome b ( 5 ) with the Delta(6)-desaturase, the co-expression with ferredoxin did not cause any differences in the GLA level. Moreover, the cultures containing the Delta(6)-desaturase co-expressed with cytochrome b (5) and ferredoxin were exogenously supplied with the intermediate electron donors, NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) and FADH(2) (flavin adenine dinucleotide, reduced form), respectively. The GLA level in these host cells increased drastically, by approximately 50%, compared to the cells without the intermediate electron donors. The data indicated that besides the level of immediate electron donors, the level of intermediate electron donors is also critical for GLA production. Therefore, if the pools of the immediate and intermediate electron donors in the cells are manipulated, the GLA production in the heterologous host will be affected.

  5. A novel omega3-fatty acid desaturase involved in the biosynthesis of eicosapentaenoic acid.

    PubMed Central

    Pereira, Suzette L; Huang, Yung-Sheng; Bobik, Emil G; Kinney, Anthony J; Stecca, Kevin L; Packer, Jeremy C L; Mukerji, Pradip

    2004-01-01

    Long-chain n-3 PUFAs (polyunsaturated fatty acids) such as EPA (eicosapentaenoic acid; 20:5 n-3) have important therapeutic and nutritional benefits in humans. In plants, cyanobacteria and nematodes, omega3-desaturases catalyse the formation of these n-3 fatty acids from n-6 fatty acid precursors. Here we describe the isolation and characterization of a gene ( sdd17 ) derived from an EPA-rich fungus, Saprolegnia diclina, that encodes a novel omega3-desaturase. This gene was isolated by PCR amplification of an S. diclina cDNA library using oligonucleotide primers corresponding to conserved regions of known omega3-desaturases. Expression of this gene in Saccharomyces cerevisiae, in the presence of various fatty acid substrates, revealed that the recombinant protein could exclusively desaturate 20-carbon n-6 fatty acid substrates with a distinct preference for ARA (arachidonic acid; 20:4 n-6), converting it into EPA. This activity differs from that of the known omega3-desaturases from any organism. Plant and cyanobacterial omega3-desaturases exclusively desaturate 18-carbon n-6 PUFAs, and a Caenorhabditis elegans omega3-desaturase preferentially desaturated 18-carbon PUFAs over 20-carbon substrates, and could not convert ARA into EPA when expressed in yeast. The sdd17 -encoded desaturase was also functional in transgenic somatic soya bean embryos, resulting in the production of EPA from exogenously supplied ARA, thus demonstrating its potential for use in the production of EPA in transgenic oilseed crops. PMID:14651475

  6. A multifunctional desaturase involved in the biosynthesis of the processionary moth sex pheromone

    PubMed Central

    Serra, Montserrat; Piña, Benjamin; Abad, José Luis; Camps, Francisco; Fabriàs, Gemma

    2007-01-01

    The sex pheromone of the female processionary moth, Thaumetopoea pityocampa, is a unique C16 enyne acetate that is biosynthesized from palmitic acid. Three consecutive desaturation reactions transform this saturated precursor into the triunsaturated fatty acyl intermediate: formation of (Z)-11-hexadecenoic acid, acetylenation to 11-hexadecynoic acid, and final Δ13 desaturation to (Z)-13-hexadecen-11-ynoic acid. By using degenerate primers common to all reported insect desaturases, a single cDNA sequence was isolated from total RNA of T. pityocampa female pheromone glands. The full-length transcript of this putative desaturase was expressed in elo1Δ/ole1Δ yeast mutants (both elongase 1 and Δ9 desaturase-deficient) for functional assays. The construct fully rescued the Δole1 yeast phenotype, confirming its desaturase activity. Analysis of the unsaturated products from transformed yeast extracts demonstrated that the cloned enzyme showed Δ11 desaturase, Δ11 acetylenase, and Δ13 desaturase activities. Therefore, this single desaturase may account for the three desaturation steps involved in the sex pheromone biosynthetic pathway of the processionary moth. PMID:17921252

  7. Expression and evolution of delta9 and delta11 desaturase genes in the moth Spodoptera littoralis.

    PubMed

    Rodríguez, Sergio; Hao, Guixia; Liu, Weitian; Piña, Benjamín; Rooney, Alejandro P; Camps, Francisco; Roelofs, Wendell L; Fabriàs, Gemma

    2004-12-01

    Desaturation of fatty acids is a key reaction in the biosynthesis of moth sex pheromones. The main component of Spodoptera littoralis sex pheromone blend is produced by the action of Delta11 and Delta9 desaturases. In this article, we report on the cloning of four desaturase-like genes in this species: one from the fat body (Sls-FL1) and three (Sls-FL2, Sls-FL3 and Sls-FL4) from the pheromone gland. By means of a computational/phylogenetic method, as well as functional assays, the desaturase gene products have been characterized. The fat body gene expressed a Delta9 desaturase that produced (Z)-9-hexadecenoic and (Z)-9-octadecenoic acids in a (1:4.5) ratio, whereas the pheromone gland Sls-FL2 expressed a Delta9 desaturase that produced (Z)-9-hexadecenoic and (Z)-9-octadecenoic acids in a (1.5:1) ratio. Although both Delta9 desaturases produced (Z)-9-tetradecenoic acid from myristic acid, transformed yeast grown in the presence of a mixture of myristic and (E)-11-tetradecenoic acids produced (Z,E)-9,11-tetradecadienoic acid, but not (Z)-9-tetradecenoic acid. The Sls-FL3 gene expressed a protein that produced a mixture of (E)-11-tetradecenoic, (Z)-11-tetradecenoic, (Z)-11-hexadecenoic and (Z)-11-octadecenoic acids in a 5:4:60:31 ratio. Despite having all the characteristics of a desaturase gene, no function could be found for Sls-FL4.

  8. Fatty acid composition and desaturase gene expression in flax (Linum usitatissimum L.).

    PubMed

    Thambugala, Dinushika; Cloutier, Sylvie

    2014-11-01

    Little is known about the relationship between expression levels of fatty acid desaturase genes during seed development and fatty acid (FA) composition in flax. In the present study, we looked at promoter structural variations of six FA desaturase genes and their relative expression throughout seed development. Computational analysis of the nucleotide sequences of the sad1, sad2, fad2a, fad2b, fad3a and fad3b promoters showed several basic transcriptional elements including CAAT and TATA boxes, and several putative target-binding sites for transcription factors, which have been reported to be involved in the regulation of lipid metabolism. Using semi-quantitative reverse transcriptase PCR, the expression patterns throughout seed development of the six FA desaturase genes were measured in six flax genotypes that differed for FA composition but that carried the same desaturase isoforms. FA composition data were determined by phenotyping the field grown genotypes over four years in two environments. All six genes displayed a bell-shaped pattern of expression peaking at 20 or 24 days after anthesis. Sad2 was the most highly expressed. The expression of all six desaturase genes did not differ significantly between genotypes (P = 0.1400), hence there were no correlations between FA desaturase gene expression and variations in FA composition in relatively low, intermediate and high linolenic acid genotypes expressing identical isoforms for all six desaturases. These results provide further clues towards understanding the genetic factors responsible for FA composition in flax.

  9. Nicotine affects hydrogen sulfide concentrations in mouse kidney and heart but not in brain and liver tissues.

    PubMed

    Wiliński, Jerzy; Wiliński, Bogdan; Somogyi, Eugeniusz; Piotrowska, Joanna; Kameczura, Tomasz; Zygmunt, Małgorzata

    2017-01-01

    Nicotine, a potent parasympathomimetic alkaloid with stimulant effects, is contributing to addictive properties of tobacco smoking and is though used in the smoking cessation therapy. Hydrogen sulfide (H2S) is involved in physiology and pathophysiology of various systems in mammals. The interactions between nicotine and H2S are not fully recognized. The aim of the study is to assess the influence of nicotine on the H2S tissue concentrations in different mouse organs. Adult CBA male mice were administered intraperitoneally 1.5 mg/kg b.w. per day of nicotine (group D1, n = 10) or 3 mg/ kg b.w. per day of nicotine (group D2, n = 10). The control group (n = 10) received physiological saline. The measurements of the free and acid-labile H2S tissue concentrations were performed with the Siegel spectrophotometric modi ed method. ere was a significant increase in H2S concentrations in both nicotine doses groups in the kidney (D1 by 54.2%, D2 by 40.0%). In the heart the higher nicotine dose caused a marked decrease in H2S tissue level (by 65.4%), while the lower dose did not affect H2S content. Nicotine administration had no effect on H2S concentrations in the brain and liver. In conclusion, nicotine affects H2S tissue concentrations in kidney and heart but not in the liver and brain tissues.

  10. Factors affecting drug-induced liver injury: antithyroid drugs as instances

    PubMed Central

    Niknahad, Hossein; Jamshidzadeh, Akram; Abdoli, Narges

    2014-01-01

    Methimazole and propylthiouracil have been used in the management of hyperthyroidism for more than half a century. However, hepatotoxicity is one of the most deleterious side effects associated with these medications. The mechanism(s) of hepatic injury induced by antithyroid agents is not fully recognized yet. Furthermore, there are no specific tools for predicting the occurrence of hepatotoxicity induced by these drugs. The purpose of this article is to give an overview on possible susceptibility factors in liver injury induced by antithyroid agents. Age, gender, metabolism characteristics, alcohol consumption, underlying diseases, immunologic mechanisms, and drug interactions are involved in enhancing antithyroid drugs-induced hepatic damage. An outline on the clinically used treatments for antithyroid drugs-induced hepatotoxicity and the potential therapeutic strategies found to be effective against this complication are also discussed. PMID:25320726

  11. DGAT1-deficiency affects the cellular distribution of hepatic retinoid and attenuates the progression of CCl4-induced liver fibrosis

    PubMed Central

    Yuen, Jason J.; Lee, Seung-Ah; Jiang, Hongfeng; Brun, Pierre-Jacques

    2015-01-01

    Background Diacylglycerol O-acyltransferase 1 (DGAT1) catalyzes the final step of triglyceride synthesis, transferring an acyl group from acyl-CoA to diacylglycerol. DGAT1 also catalyzes the acyl-CoA-dependent formation of retinyl esters in vitro and in mouse intestine and skin. Although DGAT1 is expressed in both hepatocytes and hepatic stellate cells (HSCs), we reported genetic and nutritional studies that established that DGAT1 does not contribute to retinyl ester formation in the liver. Methods We now have explored in more depth the role(s) of DGAT1 in hepatic retinoid metabolism and storage. Results Our data show that DGAT1 affects the cellular distribution between hepatocytes and HSCs of stored and newly absorbed dietary retinol. For livers of Dgat1-deficient mice, a greater percentage of stored retinyl ester is present in HSCs at the expense of hepatocytes. This is also true for newly absorbed oral [3H]retinol. These differences are associated with significantly increased expression, by 2.8-fold, of cellular retinol-binding protein, type I (RBP1) in freshly isolated HSCs from Dgat1-deficient mice, raising the possibility that RBP1, which contributes to retinol uptake into cells and retinyl ester synthesis, accounts for the differences. We further show that the retinyl ester-containing lipid droplets in HSCs are affected in Dgat1-null mice, being fewer in number but, on average, larger than in wild type (WT) HSCs. Finally, we demonstrate that DGAT1 affects experimentally induced HSC activation in vivo but that this effect is independent of altered retinoic acid availability or effects on gene expression. Conclusions Our studies establish that DGAT1 has a role in hepatic retinoid storage and metabolism, but this does not involve direct actions of DGAT1 in retinyl ester synthesis. PMID:26151058

  12. 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.

  13. Santalbic acid from quandong kernels and oil fed to rats affects kidney and liver P450.

    PubMed

    Jones, G P; Watson, T G; Sinclair, A J; Birkett, A; Dunt, N; Nair, S S; Tonkin, S Y

    1999-09-01

    Kernels of the plant Santalum acuminatum (quandong) are eaten as Australian 'bush foods'. They are rich in oil and contain relatively large amounts of the acetylenic fatty acid, santalbic acid (trans-11-octadecen-9-ynoic acid), whose chemical structure is unlike that of normal dietary fatty acids. When rats were fed high fat diets in which oil from quandong kernels supplied 50% of dietary energy, the proportion of santalbic acid absorbed was more than 90%. Feeding quandong oil elevated not only total hepatic cytochrome P450 but also the cytochrome P450 4A subgroup of enzymes as shown by a specific immunoblotting technique. A purified methyl santalbate preparation isolated from quandong oil was fed to rats at 9% of dietary energy for 4 days and this also elevated cytochrome P450 4A in both kidney and liver microsomes in comparison with methyl esters from canola oil. Santalbic acid appears to be metabolized differently from the usual dietary fatty acids and the consumption of oil from quandong kernels may cause perturbations in normal fatty acid biochemistry.

  14. 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. © 2013 Elsevier Ltd. All rights reserved.

  15. Factors affecting the translocation of oxaloacetate and l-malate into rat liver mitochondria

    PubMed Central

    Haslam, J. M.; Griffiths, D. E.

    1968-01-01

    1. The rates of translocation of oxaloacetate and l-malate into rat liver mitochondria were measured by a direct spectrophotometric assay. 2. Penetration obeyed Michaelis–Menten kinetics, and apparent Km values were 40μm for oxaloacetate and 0·13mm for l-malate. 3. Arrhenius plots of the temperature-dependence of rates of penetration gave activation energies of +10kcal./mole for oxaloacetate and +8kcal./mole for l-malate. 4. The translocation of both oxaloacetate and l-malate was competitively inhibited by d-malate, succinate, malonate, meso-tartrate, maleate and citraconate. The Ki values of these inhibitors were similar for the penetration of both oxaloacetate and l-malate. 5. Rates of penetration were stimulated by NNN′N′-tetramethyl-p-phenylenediamine dihydrochloride plus ascorbate under aerobic conditions or by ATP under anaerobic conditions. 6. The energy-dependent stimulation of translocation was abolished by uncouplers of oxidative phosphorylation. Oligomycin A, aurovertin, octyl-guanidine and atractyloside prevented the stimulation by ATP, but did not inhibit the stimulation by NNN′N′-tetramethyl-p-phenylenediamine dihydrochloride plus ascorbate. 7. Mitochondria prepared in the presence of ethylene-dioxybis(ethyleneamino)tetra-acetic acid did not exhibit the energy-dependent translocation, but this could be restored by the addition of 50μm-calcium chloride. 8. Valinomycin or gramicidin plus potassium chloride enhanced the energy-dependent translocation of oxaloacetate and l-malate. 9. Addition of oxaloacetate stimulated the adenosine triphosphatase activity of the mitochondria, and the ratio of `extra' oxaloacetate translocation to `extra' adenosine triphosphatase activity was 1·6:1. 10. Possible mechanisms for the energy-dependent entry of oxaloacetate and l-malate into mitochondria are discussed in relation to the above results. PMID:4235143

  16. Fructose liquid and solid formulations differently affect gut integrity, microbiota composition and related liver toxicity: a comparative in vivo study.

    PubMed

    Mastrocola, Raffaella; Ferrocino, Ilario; Liberto, Erica; Chiazza, Fausto; Cento, Alessia Sofia; Collotta, Debora; Querio, Giulia; Nigro, Debora; Bitonto, Valeria; Cutrin, Juan Carlos; Rantsiou, Kalliopi; Durante, Mariaconcetta; Masini, Emanuela; Aragno, Manuela; Cordero, Chiara; Cocolin, Luca; Collino, Massimo

    2018-05-01

    Despite clinical findings suggesting that the form (liquid versus solid) of the sugars may significantly affect the development of metabolic diseases, no experimental data are available on the impact of their formulations on gut microbiota, integrity and hepatic outcomes. In the present sudy, C57Bl/6j mice were fed a standard diet plus water (SD), a standard diet plus 60% fructose syrup (L-Fr) or a 60% fructose solid diet plus water (S-Fr) for 12 weeks. Gut microbiota was characterized through 16S rRNA phylogenetic profiling and shotgun sequencing of microbial genes in ileum content and related volatilome profiling. Fructose feeding led to alterations of the gut microbiota depending on the fructose formulation, with increased colonization by Clostridium, Oscillospira and Clostridiales phyla in the S-Fr group and Bacteroides, Lactobacillus, Lachnospiraceae and Dorea in the L-Fr. S-Fr evoked the highest accumulation of advanced glycation end products and barrier injury in the ileum intestinal mucosa. These effects were associated to a stronger activation of the lipopolysaccharide-dependent proinflammatory TLR4/NLRP3 inflammasome pathway in the liver of S-Fr mice than of L-Fr mice. In contrast, L-Fr intake induced higher levels of hepatosteatosis and markers of fibrosis than S-Fr. Fructose-induced ex novo lipogenesis with production of SCFA and MCFA was confirmed by metagenomic analysis. These results suggest that consumption of fructose under different forms, liquid or solid, may differently affect gut microbiota, thus leading to impairment in intestinal mucosa integrity and liver homeostasis. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Fatty acid desaturase 1 knockout mice are lean with improved glycemic control and decreased development of atheromatous plaque

    PubMed Central

    Powell, David R; Gay, Jason P; Smith, Melinda; Wilganowski, Nathaniel; Harris, Angela; Holland, Autumn; Reyes, Maricela; Kirkham, Laura; Kirkpatrick, Laura L; Zambrowicz, Brian; Hansen, Gwenn; Platt, Kenneth A; van Sligtenhorst, Isaac; Ding, Zhi-Ming; Desai, Urvi

    2016-01-01

    Delta-5 desaturase (D5D) and delta-6 desaturase (D6D), encoded by fatty acid desaturase 1 (FADS1) and FADS2 genes, respectively, are enzymes in the synthetic pathways for ω3, ω6, and ω9 polyunsaturated fatty acids (PUFAs). Although PUFAs appear to be involved in mammalian metabolic pathways, the physiologic effect of isolated D5D deficiency on these pathways is unclear. After generating >4,650 knockouts (KOs) of independent mouse genes and analyzing them in our high-throughput phenotypic screen, we found that Fads1 KO mice were among the leanest of 3,651 chow-fed KO lines analyzed for body composition and were among the most glucose tolerant of 2,489 high-fat-diet-fed KO lines analyzed by oral glucose tolerance test. In confirmatory studies, chow- or high-fat-diet-fed Fads1 KO mice were leaner than wild-type (WT) littermates; when data from multiple cohorts of adult mice were combined, body fat was 38% and 31% lower in Fads1 male and female KO mice, respectively. Fads1 KO mice also had lower glucose and insulin excursions during oral glucose tolerance tests along with lower fasting glucose, insulin, triglyceride, and total cholesterol levels. In additional studies using a vascular injury model, Fads1 KO mice had significantly decreased femoral artery intima/media ratios consistent with a decreased inflammatory response in their arterial wall. Based on this result, we bred Fads1 KO and WT mice onto an ApoE KO background and fed them a Western diet for 14 weeks; in this atherogenic environment, aortic trees of Fads1 KO mice had 40% less atheromatous plaque compared to WT littermates. Importantly, PUFA levels measured in brain and liver phospholipid fractions of Fads1 KO mice were consistent with decreased D5D activity and normal D6D activity. The beneficial metabolic phenotype demonstrated in Fads1 KO mice suggests that selective D5D inhibitors may be useful in the treatment of human obesity, diabetes, and atherosclerotic cardiovascular disease. PMID:27382320

  18. Evolution of the Insect Desaturase Gene Family with an Emphasis on Social Hymenoptera

    PubMed Central

    Helmkampf, Martin; Cash, Elizabeth; Gadau, Jürgen

    2015-01-01

    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. PMID:25425561

  19. Transcriptomics, metabolomics and histology indicate that high-carbohydrate diet negatively affects the liver health of blunt snout bream (Megalobrama amblycephala).

    PubMed

    Prisingkorn, Wassana; Prathomya, Panita; Jakovlić, Ivan; Liu, Han; Zhao, Yu-Hua; Wang, Wei-Min

    2017-11-09

    Global trend of the introduction of high levels of relatively cheap carbohydrates to reduce the amount of costly protein in the aquatic animal feed production has affected the aquaculture of an economically important cyprinid fish, blunt snout bream (Megalobrama amblycephala). This dietary shift has resulted in increased prevalence of metabolic disorders, often causing economic losses. High dietary intake of carbohydrates, associated with obesity, is one of the major causes of non-alcoholic fatty liver disease (NAFLD) in humans. We have conducted an eight-week feeding trial to better understand how a high-carbohydrate diet (HCBD) affects the liver health in this fish. Hepatosomatic index and lipid content were significantly (P < 0.05) higher in the HCBD group. Histology results also suggested pathological changes in the livers of HCBD group, with excessive lipid accumulation and indication of liver damage. Metabolomics and serum biochemistry analyses showed that a number of metabolites indicative of liver damage were increased in the HCBD group. This group also exhibited low levels of betaine, which is a metabolite crucial for maintaining the healthy liver functions. Transcriptomic and qPCR analyses indicated that HCBD had a strong impact on the expression of a large number of genes associated with the NAFLD and insulin signalling pathways, which may lead to the development of insulin resistance in hepatocytes, pathological liver changes, and eventually the NAFLD. Transcriptomics, metabolomics and histology results all indicate early symptoms of liver damage. However whether these would actually lead to the development of NAFLD after a longer period of time, remains inconclusive. Additionally, a very high number of upregulated genes in the HCBD group associated with several neurodegenerative diseases is a strong indication of neurodegenerative changes caused by the high-carbohydrate diet in blunt snout bream. This suggests that fish might present a good model to

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

    PubMed

    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.

  1. Inducing effect of clofibric acid on stearoyl-CoA desaturase in intestinal mucosa of rats.

    PubMed

    Yamazaki, Tohru; Kadokura, Makiko; Mutoh, Yuki; Sakamoto, Takeshi; Okazaki, Mari; Mitsumoto, Atsushi; Kawashima, Yoichi; Kudo, Naomi

    2014-12-01

    Fibrates have been reported to elevate the hepatic proportion of oleic acid (18:1n-9) through inducing stearoyl-CoA desaturase (SCD). Despite abundant studies on the regulation of SCD in the liver, little is known about this issue in the small intestine. The present study aimed to investigate the effect of clofibric acid on the fatty acid profile, particularly monounsaturated fatty acids (MUFA), and the SCD expression in intestinal mucosa. Treatment of rats with a diet containing 0.5% (w/w) clofibric acid for 7 days changed the MUFA profile of total lipids in intestinal mucosa; the proportion of 18:1n-9 was significantly increased, whereas those of palmitoleic (16:1n-7) and cis-vaccenic (18:1n-7) acids were not changed. Upon the treatment with clofibric acid, SCD was induced and the gene expression of SCD1, SCD2, and fatty acid elongase (Elovl) 6 was up-regulated, but that of Elovl5 was unaffected. Fat-free diet feeding for 28 days increased the proportions of 16:1n-7 and 18:1n-7, but did not effectively change that of 18:1n-9, in intestinal mucosa. Fat-free diet feeding up-regulated the gene expression of SCD1, but not that of SCD2, Elovl6, or Elovl5. These results indicate that intestinal mucosa significantly changes its MUFA profile in response to challenges by clofibric acid and a fat-free diet and suggest that up-regulation of the gene expression of SCD along with Elovl6 is indispensable to elevate the proportion of 18:1n-9 in intestinal mucosa.

  2. Characterization of Stearoyl-CoA Desaturases from a Psychrophilic Antarctic Copepod, Tigriopus kingsejongensis.

    PubMed

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

    2016-10-01

    Stearoyl-CoA desaturase is a key regulator in fatty acid metabolism that catalyzes the desaturation of stearic acid to oleic acid and controls the intracellular levels of monounsaturated fatty acids (MUFAs). Two stearoyl-CoA desaturases (SCD, Δ9 desaturases) genes were identified in an Antarctic copepod, Tigriopus kingsejongensis, that was collected in a tidal pool near the King Sejong Station, King George Island, Antarctica. Full-length complementary DNA (cDNA) sequences of two T. kingsejongensis SCDs (TkSCDs) were obtained from next-generation sequencing and isolated by reverse transcription PCR. DNA sequence lengths of the open reading frames of TkSCD-1 and TkSCD-2 were determined to be 1110 and 681 bp, respectively. The molecular weights deduced from the corresponding genes were estimated to be 43.1 kDa (TkSCD-1) and 26.1 kDa (TkSCD-2). The amino acid sequences were compared with those of fatty acid desaturases and sterol desaturases from various organisms and used to analyze the relationships among TkSCDs. As assessed by heterologous expression of recombinant proteins in Escherichia coli, the enzymatic functions of both stearoyl-CoA desaturases revealed that the amount of C16:1 and C18:1 fatty acids increased by greater than 3-fold after induction with isopropyl β-D-thiogalactopyranoside. In particular, C18:1 fatty acid production increased greater than 10-fold in E. coli expressing TkSCD-1 and TkSCD-2. The results of this study suggest that both SCD genes from an Antarctic marine copepod encode a functional desaturase that is capable of increasing the amounts of palmitoleic acid and oleic acid in a prokaryotic expression system.

  3. Functional screening of a novel Δ15 fatty acid desaturase from the coccolithophorid Emiliania huxleyi.

    PubMed

    Kotajima, Tomonori; Shiraiwa, Yoshihiro; Suzuki, Iwane

    2014-10-01

    The coccolithophorid Emiliania huxleyi is a bloom-forming marine phytoplankton thought to play a key role as a biological pump that transfers carbon from the surface to the bottom of the ocean, thus contributing to the global carbon cycle. This alga is also known to accumulate a variety of polyunsaturated fatty acids. At 25°C, E. huxleyi produces mainly 14:0, 18:4n-3, 18:5n-3 and 22:6n-3. When the cells were transferred from 25°C to 15°C, the amount of unsaturated fatty acids, i.e. 18:1n-9, 18:3n-3 and 18:5n-3, gradually increased. Among the predicted desaturase genes whose expression levels were up-regulated at low temperature, we identified a gene encoding novel ∆15 fatty acid desaturase, EhDES15, involved in the production of n-3 polyunsaturated fatty acids in E. huxleyi. This desaturase contains a putative transit sequence for localization in chloroplasts and a ∆6 desaturase-like domain, but it does not contain a cytochrome b5 domain nor typical His-boxes found in ∆15 desaturases. Heterologous expression of EhDES15 cDNA in cyanobacterium Synechocystis sp. PCC 6803 cells increased the level of n-3 fatty acid species, which are produced at low levels in wild-type cells grown at 30°C. The orthologous genes are only conserved in the genomes of prasinophytes and cryptophytes. The His-boxes conserved in orthologues varied from that of the canonical ∆15 desaturases. These results suggested the gene encodes a novel ∆15 desaturase responsible for the synthesis of 18:3n-3 from 18:2n-6 in E. huxleyi. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. 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

  5. Temperature-dependent endogenous oxygen concentration regulates microsomal oleate desaturase in developing sunflower seeds.

    PubMed

    Rolletschek, Hardy; Borisjuk, Ljudmilla; Sánchez-García, Alicia; Gotor, Cecilia; Romero, Luis C; Martínez-Rivas, José M; Mancha, Manuel

    2007-01-01

    Oleoyl-phosphatidylcholine desaturase (FAD2) is a key enzyme involved in fatty acid desaturation in oilseeds, which is affected by environmental temperature. The results of this study show that FAD2 is regulated in vivo via temperature-dependent endogenous oxygen concentrations in developing sunflower (Helianthus annuus L.) seeds. By combining in vivo oxygen profiling, in situ hybridization of FAD2 genes, an assay of energy status, fatty acid analysis, and an in vitro FAD2 enzyme activity assay, it is shown that: (i) the oil-storing embryo is characterized by a very low oxygen level that is developmentally regulated. Oxygen supply is mainly limited by the thin seed coat. (ii) Elevations of external oxygen supply raised the energy status of seed and produced a dramatic increase of the FAD2 enzyme activity as well as the linoleic acid content. (iii) A clear negative correlation exists between temperature and internal oxygen concentration. The changes occurred almost instantly and the effect was fully reversible. The results indicate that the internal oxygen level acts as a key regulator for the activity of the FAD2 enzyme. It is concluded that a major mechanism by which temperature modifies the unsaturation degree of the sunflower oil is through its effect on dissolved oxygen levels in the developing seed.

  6. Ketogenic diet delays the phase of circadian rhythms and does not affect AMP-activated protein kinase (AMPK) in mouse liver.

    PubMed

    Genzer, Yoni; Dadon, Maayan; Burg, Chen; Chapnik, Nava; Froy, Oren

    2015-12-05

    Ketogenic diet (KD) is used for weight loss or to treat epilepsy. KD leads to liver AMP-activated protein kinase (AMPK) activation, which would be expected to inhibit gluconeogenesis. However, KD leads to increased hepatic glucose output. As AMPK and its active phosphorylated form (pAMPK) show circadian oscillation, this discrepancy could stem from wrong-time-of-day sampling. The effect of KD was tested on mouse clock gene expression, AMPK, mTOR, SIRT1 and locomotor activity for 2 months and compared to low-fat diet (LFD). KD led to 1.5-fold increased levels of blood glucose and insulin. Brain pAMPK/AMPK ratio was 40% higher under KD, whereas that in liver was not affected. KD led to 40% and 20% down-regulation of the ratio of pP70S6K/P70S6K, the downstream target of mTOR, in the brain and liver, respectively. SIRT1 levels were 40% higher in the brain, but 40% lower in the liver of KD-fed mice. Clock genes showed delayed rhythms under KD. In the brain of KD-fed mice, amplitudes of clock genes were down-regulated, whereas 6-fold up-regulation was found in the liver. The metabolic state under KD indicates reduced satiety in the brain and reduced anabolism alongside increased gluconeogenesis in the liver. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Sex Pheromone Evolution Is Associated with Differential Regulation of the Same Desaturase Gene in Two Genera of Leafroller Moths

    PubMed Central

    Albre, Jérôme; Liénard, Marjorie A.; Sirey, Tamara M.; Schmidt, Silvia; Tooman, Leah K.; Carraher, Colm; Greenwood, David R.; Löfstedt, Christer; Newcomb, Richard D.

    2012-01-01

    Chemical signals are prevalent in sexual communication systems. Mate recognition has been extensively studied within the Lepidoptera, where the production and recognition of species-specific sex pheromone signals are typically the defining character. While the specific blend of compounds that makes up the sex pheromones of many species has been characterized, the molecular mechanisms underpinning the evolution of pheromone-based mate recognition systems remain largely unknown. We have focused on two sets of sibling species within the leafroller moth genera Ctenopseustis and Planotortrix that have rapidly evolved the use of distinct sex pheromone blends. The compounds within these blends differ almost exclusively in the relative position of double bonds that are introduced by desaturase enzymes. Of the six desaturase orthologs isolated from all four species, functional analyses in yeast and gene expression in pheromone glands implicate three in pheromone biosynthesis, two Δ9-desaturases, and a Δ10-desaturase, while the remaining three desaturases include a Δ6-desaturase, a terminal desaturase, and a non-functional desaturase. Comparative quantitative real-time PCR reveals that the Δ10-desaturase is differentially expressed in the pheromone glands of the two sets of sibling species, consistent with differences in the pheromone blend in both species pairs. In the pheromone glands of species that utilize (Z)-8-tetradecenyl acetate as sex pheromone component (Ctenopseustis obliquana and Planotortrix octo), the expression levels of the Δ10-desaturase are significantly higher than in the pheromone glands of their respective sibling species (C. herana and P. excessana). Our results demonstrate that interspecific sex pheromone differences are associated with differential regulation of the same desaturase gene in two genera of moths. We suggest that differential gene regulation among members of a multigene family may be an important mechanism of molecular innovation in

  8. Ablation of systemic SIRT1 activity promotes nonalcoholic fatty liver disease by affecting liver-mesenteric adipose tissue fatty acid mobilization

    USDA-ARS?s Scientific Manuscript database

    The incidence of nonalcoholic fatty liver disease (NAFLD) is escalating paralleled with obesity rates in both adults and children. Mammalian sirtuin 1 (SIRT1), a highly conserved NAD+-dependent protein deacetylase, has been identified as a metabolic regulator of lipid homeostasis and a potential tar...

  9. [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.

  10. cDNA nucleotide sequence coding for stearoyl-CoA desaturase and its expression in the zebrafish (Danio rerio) embryo.

    PubMed

    Hsieh, S L; Liu, R W; Wu, C H; Cheng, W T; Kuo, Ching-Ming

    2003-12-01

    A cDNA sequence of stearoyl-CoA desaturase (SCD) was determined from zebrafish (Danio rerio) and compared to the corresponding genes in several teleosts. Zebrafish SCD cDNA has a size of 1,061 bp, encodes a polypeptide of 325 amino acids, and shares 88, 85, 84, and 83% similarities with tilapia (Oreochromis mossambicus), grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), and milkfish (Chanos chanos), respectively. This 1,061 bp sequence specifies a protein that, in common with other fatty acid desaturases, contains three histidine boxes, believed to be involved in catalysis. These observations suggested that SCD genes are highly conserved. In addition, an oligonucleotide probe complementary to zebrafish SCD mRNA was hybridized to mRNA of approximately 396 bases with Northern blot analysis. The Northern blot and RT-PCR analyses showed that the SCD mRNA was expressed predominantly in the liver, intestine, gill, and muscle, while a lower level was found in the brain. Furthermore, we utilized whole-mount in situ hybridization and real-time quantitative RT-PCR to identify expression of the zebrafish SCD gene at five different stages of development. This revealed that very high levels of transcripts were found in zebrafish at all stages during embryogenesis and early development. Copyright 2003 Wiley-Liss, Inc.

  11. Liver metastases

    MedlinePlus

    Metastases to the liver; Metastatic liver cancer; Liver cancer - metastatic; Colorectal cancer - liver metastases; Colon cancer - liver metastases; Esophageal cancer - liver metastases; Lung cancer - liver metastases; Melanoma - liver metastases

  12. Functional identification and regulatory analysis of Δ6-fatty acid desaturase from the oleaginous fungus Mucor sp. EIM-10.

    PubMed

    Jiang, Xianzhang; Liu, Hongjiao; Niu, Yongchao; Qi, Feng; Zhang, Mingliang; Huang, Jianzhong

    2017-03-01

    To enlarge the diversity of the desaturases associated with PUFA biosynthesis and to better understand the transcriptional regulation of desaturases, a Δ 6 -desaturase gene (Md6) from Mucor sp. and its 5'-upstream sequence was functionally identified in Saccharomyces cerevisiae. Expression of the Δ 6 -fatty acid desaturase (Md6) in S. cerevisiae showed that Md6 could convert linolenic acid to γ-linolenic acid. Computational analysis of the promoter of Md6 suggested it contains several eukaryotic fundamental transcription regulatory elements. In vivo functional analysis of the promoter showed the 5'-upstream sequence of Md6 could initiate expression of GFP and Md6 itself in S. cerevisiae. A series deletion analysis of the promoter suggested that sequence between -919 to -784 bp (relative to start site) named as eMd6 is the key factor for high activity of Δ 6 -desaturase. The activity of Δ 6 -desaturase was increased by 2.8-fold and 2.5-fold when the eMd6 sequence was placed upstream of -434 with forward or reverse orientations respectively. To our best knowledge, the native promoter of Md6 from Mucor is the strongest promoter for Δ 6 -desaturase reported so far and the sequence between -919 to -784 bp is an enhancer for Δ 6 -desaturase activity.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  14. Menhaden oil, but not safflower or soybean oil, aids in restoring the polyunsaturated fatty acid profile in the novel delta-6-desaturase null mouse

    PubMed Central

    2012-01-01

    Background Polyunsaturated fatty acids (PUFA) have diverse biological effects, from promoting inflammation to preventing cancer and heart disease. Growing evidence suggests that individual PUFA may have independent effects in health and disease. The individual roles of the two essential PUFA, linoleic acid (LA) and α-linolenic acid (ALA), have been difficult to discern from the actions of their highly unsaturated fatty acid (HUFA) downstream metabolites. This issue has recently been addressed through the development of the Δ-6 desaturase knock out (D6KO) mouse, which lacks the rate limiting Δ-6 desaturase enzyme and therefore cannot metabolize LA or ALA. However, a potential confounder in this model is the production of novel Δ-5 desaturase (D5D) derived fatty acids when D6KO mice are fed diets containing LA and ALA, but void of arachidonic acid. Objective The aim of the present study was to characterize how the D6KO model differentially responds to diets containing the essential n-6 and n-3 PUFA, and whether the direct provision of downstream HUFA can rescue the phenotype and prevent the production of D5D fatty acids. Methodology Liver and serum phospholipid (PL) fatty acid composition was examined in D6KO and wild type mice fed i) 10% safflower oil diet (SF, LA rich) ii) 10% soy diet (SO, LA+ALA) or iii) 3% menhaden oil +7% SF diet (MD, HUFA rich) for 28 days (n = 3-7/group). Results Novel D5D fatty acids were found in liver PL of D6KO fed SF or SO-fed mice, but differed in the type of D5D fatty acid depending on diet. Conversely, MD-fed D6KO mice had a liver PL fatty acid profile similar to wild-type mice. Conclusions Through careful consideration of the dietary fatty acid composition, and especially the HUFA content in order to prevent the synthesis of D5D fatty acids, the D6KO model has the potential to elucidate the independent biological and health effects of the parent n-6 and n-3 fatty acids, LA and ALA. PMID:22642787

  15. Bleaching herbicide norflurazon inhibits phytoene desaturase by competition with the cofactors.

    PubMed

    Breitenbach, J; Zhu, C; Sandmann, G

    2001-11-01

    Cofactor requirement was determined for the heterologous expressed phytoene desaturases from the cyanobacterium Synechococcus and the higher plant Gentiana lutea. The cyanobacterial enzyme is dependent on either NAD(P) or plastoquinone, whereas only quinones such as plastoquinone can function as a cofactor for the phytoene desaturase from G. lutea. Enzyme kinetic studies were carried out to determine a possible competition between the cofactors and the bleaching herbicide norflurazon. For the Synechococcus enzyme, competition between norflurazon and NADP, as well as plastoquinone, could be demonstrated. The K(m) values for these cofactors were 6.6 mM and 0.23 microM, respectively. Inhibition of the phytoene desaturase from G. lutea by norflurazon was also competitive with respect to plastoquinone. The K(m) values of both enzymes for plastoquinone were very close.

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

    SciTech Connect

    Alloatti, Andres; Gupta, Shreedhara; Gualdron-Lopez, Melisa

    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 namedmore » 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.« less

  17. Remote control of regioselectivity in acyl-acyl carrier protein-desaturases

    PubMed Central

    Guy, Jodie E.; Whittle, Edward; Moche, Martin; Lengqvist, Johan; Lindqvist, Ylva; Shanklin, John

    2011-01-01

    Regiospecific desaturation of long-chain saturated fatty acids has been described as approaching the limits of the discriminatory power of enzymes because the substrate entirely lacks distinguishing features close to the site of dehydrogenation. To identify the elusive mechanism underlying regioselectivity, we have determined two crystal structures of the archetypal Δ9 desaturase from castor in complex with acyl carrier protein (ACP), which show the bound ACP ideally situated to position C9 and C10 of the acyl chain adjacent to the diiron active site for Δ9 desaturation. Analysis of the structures and modeling of the complex between the highly homologous ivy Δ4 desaturase and ACP, identified a residue located at the entrance to the binding cavity, Asp280 in the castor desaturase (Lys275 in the ivy desaturase), which is strictly conserved within Δ9 and Δ4 enzymes but differs between them. We hypothesized that interaction between Lys275 and the phosphate of the pantetheine, seen in the ivy model, is key to positioning C4 and C5 adjacent to the diiron center for Δ4 desaturation. Mutating castor Asp280 to Lys resulted in a major shift from Δ9 to Δ4 desaturation. Thus, interaction between desaturase side-chain 280 and phospho-serine 38 of ACP, approximately 27 Å from the site of double-bond formation, predisposes ACP binding that favors either Δ9 or Δ4 desaturation via repulsion (acidic side chain) or attraction (positively charged side chain), respectively. Understanding the mechanism underlying remote control of regioselectivity provides the foundation for reengineering desaturase enzymes to create designer chemical feedstocks that would provide alternatives to those currently obtained from petrochemicals. PMID:21930947

  18. Remote control of regioselectivity in acyl-acyl carrier protein-desaturases.

    PubMed

    Guy, Jodie E; Whittle, Edward; Moche, Martin; Lengqvist, Johan; Lindqvist, Ylva; Shanklin, John

    2011-10-04

    Regiospecific desaturation of long-chain saturated fatty acids has been described as approaching the limits of the discriminatory power of enzymes because the substrate entirely lacks distinguishing features close to the site of dehydrogenation. To identify the elusive mechanism underlying regioselectivity, we have determined two crystal structures of the archetypal Δ9 desaturase from castor in complex with acyl carrier protein (ACP), which show the bound ACP ideally situated to position C9 and C10 of the acyl chain adjacent to the diiron active site for Δ9 desaturation. Analysis of the structures and modeling of the complex between the highly homologous ivy Δ4 desaturase and ACP, identified a residue located at the entrance to the binding cavity, Asp280 in the castor desaturase (Lys275 in the ivy desaturase), which is strictly conserved within Δ9 and Δ4 enzymes but differs between them. We hypothesized that interaction between Lys275 and the phosphate of the pantetheine, seen in the ivy model, is key to positioning C4 and C5 adjacent to the diiron center for Δ4 desaturation. Mutating castor Asp280 to Lys resulted in a major shift from Δ9 to Δ4 desaturation. Thus, interaction between desaturase side-chain 280 and phospho-serine 38 of ACP, approximately 27 Å from the site of double-bond formation, predisposes ACP binding that favors either Δ9 or Δ4 desaturation via repulsion (acidic side chain) or attraction (positively charged side chain), respectively. Understanding the mechanism underlying remote control of regioselectivity provides the foundation for reengineering desaturase enzymes to create designer chemical feedstocks that would provide alternatives to those currently obtained from petrochemicals.

  19. 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

  20. Temperature Increase Negatively Affects the Fatty Acid Bioconversion Capacity of Rainbow Trout (Oncorhynchus mykiss) Fed a Linseed Oil-Based Diet.

    PubMed

    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.

  1. The GmFAD7 gene family from soybean: identification of novel genes and tissue-specific conformations of the FAD7 enzyme involved in desaturase activity.

    PubMed

    Andreu, Vanesa; Lagunas, Beatriz; Collados, Raquel; Picorel, Rafael; Alfonso, Miguel

    2010-07-01

    The FAD7 gene encodes a omega3 fatty acid desaturase which catalyses the production of trienoic fatty acids (TAs) in plant chloroplasts. A novel GmFAD7 gene (named GmFAD7-2) has been identified in soybean, with high homology to the previously annotated GmFAD7 gene. Genomic sequencing analysis together with searches at the soybean genome database further confirmed that both GmFAD7 genes were located in two different loci within the soybean genome, suggesting that the soybean omega3 plastidial desaturase FAD7 is encoded by two different paralogous genes. Both GmFAD7-1 and GmFAD7-2 genes were expressed in all soybean tissues examined, displaying their highest mRNA accumulation in leaves. This expression profile contrasted with GmFAD3A and GmFAD3B mRNA accumulation, which was very low in this tissue. These results suggested a concerted control of plastidial and reticular omega3 desaturase gene expression in soybean mature leaves. Analysis of GmFAD7 protein distribution in different soybean tissues showed that, in mature leaves, two bands were detected, coincident with the higher expression level of both GmFAD7 genes and the highest 18:3 fatty acid accumulation. By contrast, in seeds, where FAD7 activity is low, specific GmFAD7 protein conformations were observed. These GmFAD7 protein conformations were affected in vitro by changes in the redox conditions of thiol groups and iron availability. These results suggest the existence of tissue-specific post-translational regulatory mechanisms affecting the distribution and conformation of the FAD7 enzymes related with the control of its activity.

  2. Selection in Europeans on Fatty Acid Desaturases Associated with Dietary Changes

    PubMed Central

    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

    2017-01-01

    Abstract 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. PMID:28333262

  3. Arsenic trioxide suppresses liver X receptor β and enhances cholesteryl ester transfer protein expression without affecting the liver X receptor α in HepG2 cells.

    PubMed

    Cheng, Tain-Junn; Lin, Shu-Wen; Chen, Chih-Wei; Guo, How-Ran; Wang, Ying-Jang

    2016-10-25

    Chronic arsenic exposure is associated with cerebrovascular disease and the formation of atherosclerotic lesions. Our previous study demonstrated that arsenic trioxide (ATO) exposure was associated with atherosclerotic lesion formation through alterations in lipid metabolism in the reverse cholesterol transport process. In mouse livers, the expression of the liver X receptor β (LXR-β) and the cholesteryl ester transfer protein (CETP) was suppressed without any changes to the lipid profile. The aim of this study was to elucidate whether ATO contributes to atherosclerotic lesions by suppressing LXR-β and CETP levels in hepatocytes. HepG2 cells, human hepatocytes, were exposed to different ATO concentrations in vitro. Cell viability was determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. The liver X receptor α (LXR-α), LXR-β, sterol regulatory element-binding protein-1c (SREBP-1c) and CETP protein levels were measured by Western blotting, and their mRNA levels were measured by real-time PCR. Cholesterol efflux was analyzed by flow cytometry. The results showed ATO inhibited LXR-β mRNA and protein levels with a subsequent decrease in SREBP-1c protein levels and reduced cholesterol efflux from HepG2 cells into the extracellular space without influencing LXR-α mRNA and protein levels. CETP protein levels of HepG2 cells were significantly elevated under arsenic exposure. Transfection of LXR-β shRNA did not change CETP protein levels, implying that there is no cross-talk between LXR-β and CETP. In conclusion, arsenic not only inhibits LXR-β and SREBP-1c mRNA and protein levels but also independently increases CETP protein levels in HepG2 cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. ABC transporters affect the elimination and toxicity of CdTe quantum dots in liver and kidney cells

    SciTech Connect

    Chen, Mingli; Yin, Huancai; Bai, Pengli

    This paper aimed to investigate the role of adenosine triphosphate-binding cassette (ABC) transporters on the efflux and the toxicity of nanoparticles in liver and kidney cells. In this study, we synthesized CdTe quantum dots (QDs) that were monodispersed and emitted green fluorescence (maximum peak at 530 nm). Such QDs tended to accumulate in human hepatocellular carcinoma cells (HepG2), human kidney cells 2 (HK-2), and Madin-Darby canine kidney (MDCK) cells, and cause significant toxicity in all the three cell lines. Using specific inhibitors and inducers of P-glycoprotein (Pgp) and multidrug resistance associated proteins (Mrps), the cellular accumulation and subsequent toxicity ofmore » QDs in HepG2 and HK-2 cells were significantly affected, while only slight changes appeared in MDCK cells, corresponding well with the functional expressions of ABC transporters in cells. Moreover, treatment of QDs caused concentration- and time- dependent induction of ABC transporters in HepG2 and HK-2 cells, but such phenomenon was barely found in MDCK cells. Furthermore, the effects of CdTe QDs on ABC transporters were found to be greater than those of CdCl{sub 2} at equivalent concentrations of cadmium, indicating that the effects of QDs should be a combination of free Cd{sup 2+} and specific properties of QDs. Overall, these results indicated a strong dependence between the functional expressions of ABC transporters and the efflux of QDs, which could be an important reason for the modulation of QDs toxicity by ABC transporters. - Highlights: • ABC transporters contributed actively to the cellular efflux of CdTe quantum dots. • ABC transporters affected the cellular toxicity of CdTe quantum dots. • Treatment of CdTe quantum dots induced the gene expression of ABC transporters. • Free Cd{sup 2+} should be partially involved in the effects of QDs on ABC transporters. • Cellular efflux of quantum dots could be an important modulator for its toxicity.« less

  5. Liver transplant

    MedlinePlus

    ... fully working livers after a successful transplant. The donor liver is transported in a cooled salt-water (saline) ... Liver failure - liver transplant; Cirrhosis - liver transplant Images Donor liver attachment Liver transplant - series References Carrion AF, Martin ...

  6. Parallel activation of de novo lipogenesis and stearoyl-CoA desaturase activity after 3 d of high-carbohydrate feeding.

    PubMed

    Chong, Mary F-F; Hodson, Leanne; Bickerton, Alex S; Roberts, Rachel; Neville, Matt; Karpe, Fredrik; Frayn, Keith N; Fielding, Barbara A

    2008-04-01

    High-carbohydrate (HC) diets increase de novo lipogenesis (DNL), but effects on stearoyl-CoA desaturase (SCD) are not so well studied. The objective was to investigate DNL and SCD in liver and adipose tissue by using fatty acid ratios after short-term dietary intervention. Eight subjects consumed isoenergetic 3-d HC (10% fat; 75% carbohydrates) or higher fat (HF; 40% fat; 45% carbohydrates) diets (sugar to starch ratio: 60:40 for both) in a crossover study. Blood was taken from an artery and a vein draining subcutaneous adipose tissue. DNL and SCD activity were investigated by using the ratios of 16:0 to 18:2n-6 and of 16:1n-7 to 16:0, respectively. A test meal, including [U-(13)C]palmitate was given to trace dietary fatty acid incorporation into VLDL-triacylglycerol (TG). The conversion of intravenously infused [(2)H(2)]palmitic acid to [(2)H(2)]palmitoleic acid in VLDL-TG was quantified as a specific marker of hepatic SCD activity. The VLDL-TG 16:0/18:2n-6 ratio, which reflects hepatic DNL, was greater after the HC diet than after the HF diet (P = 0.02). With the HC diet, increased plasma TG concentrations correlated with 16:0/18:2n-6 ratios (r = 0.76, P = 0.028). Plasma VLDL-TG and adipose venous nonesterified fatty acid (NEFA) 16:1n-7/16:0 ratios were higher after the HC diet (fasting: P = 0.01 and P = 0.05, respectively; postprandial: P = 0.03 and P = 0.05, respectively). Changes in fasting VLDL-TG 16:0/18:2n-6 and 16:1n-7/16:0 ratios were associated (P = 0.06). The contribution of total fatty acids from splanchnic sources (including DNL) was higher after the HC diet (P = 0.02). Expression of lipogenic genes in subcutaneous adipose tissue was not significantly affected by diet. Parallel activation of DNL and SCD was found after a short period of HC feeding.

  7. Multivariate analysis of the factors affecting attitude toward living liver donation among workers in surgical services in Spanish, Mexican, and Cuban hospitals.

    PubMed

    Ríos, A; López-Navas, A; Ayala-García, M A; Sebastián, M J; Abdo-Cuza, A; Febrero, B; Ramírez, E J; Muñoz, G; Palacios, G; Suárez-López, J; Castellanos, R; Rodríguez, J S; Martínez, M A; Nieto, A; Martínez-Alarcón, L; Ramis, G; Ramírez, P; Parrilla, P

    2012-01-01

    Current liver donation rates are insufficient to cover transplant needs. Therefore, it is essential to promote living liver donation (LLD) given the ever decreasing morbidity and mortality in the donor and the improving results in the recipient. LLD is becoming increasingly accepted. However, in the health care system, a percentage of the personnel are not in favor. To analyze the attitude of personnel in surgical services in Spain and Latin-America hospitals toward LLD. As part of the "International Collaborative Donor Project," a random sample was taken and stratified according to surgical service and job category in 10 hospitals; three in Spain, five in Mexico, and two in Cuba (n = 496). Attitude was evaluated using a validated survey that was completed anonymously and self-administered. Eighty-six percent (n = 425) of respondents were in favor of related living liver donation, and 30% (n = 147) were in favor if it were not related. According to country, 88% of the Mexican respondents were in favor of living liver donation, 85% of the Cubans, and 82% of the Spanish (P > .05). In the multivariate analysis of the variables with most weight affecting attitude toward LLD, the following significant associations were found: (1) a favourable attitude toward living kidney donation (odds ratio [OR] = 91; P < .001); (2) acceptance of a donated living liver if one were needed (OR = 11; P < .001); and (3) family discussion about donation and transplantation (OR = 2.581; P = .037). Attitude toward related living liver donation was very favorable among hospital personnel in Spanish and Latin American surgical services. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Testosterone and estradiol treatments differently affect pituitary-thyroid axis and liver deiodinase 1 activity in orchidectomized middle-aged rats.

    PubMed

    Šošić-Jurjević, B; Filipović, B; Renko, K; Miler, M; Trifunović, S; Ajdžanovič, V; Kӧhrle, J; Milošević, V

    2015-12-01

    We previously reported that orchidectomy (Orx) of middle-aged rats (15-16-month-old; MA) slightly affected pituitary-thyroid axis, but decreased liver deiodinase (Dio) type 1 and pituitary Dio2 enzyme activities. At present, we examined the effects of subsequent testosterone-propionate treatment (5mg/kg; Orx+T), and compared the effects of testosterone with the effects of estradiol-dipropionate (0.06mg/kg; Orx+E) treatment. Hormones were subcutaneously administered, daily, for three weeks, while Orx and sham-operated (SO) controls received only the vehicle. The applied dose of T did not alter serum TSH, T4 and T3 concentrations in Orx- MA, though it increased TSH when administrated to Orx young adults (2.5-month-old; Orx-YA). However, pituitaries of Orx-MA+T rats had higher relative intensity of immunofluorescence (RIF) for TSHβ; in their thyroids we found increased volume and height of follicular epithelium, decreased volume of the colloid and higher RIF for T4-bound to thyroglobulin (Tg-T4). Liver Dio1 activity was increased. E-treatment did not affect serum hormone levels, pituitary RIF for TSHβ, or liver Dio1 activity in Orx-MA rats. Thyroids had decreased relative volume and height of follicular epithelium, increased relative volume of the colloid, decreased volume of sodium-iodide symporter-immunopositive epithelium and lower RIF for Tg-T4. Detected changes were statistically significant. In conclusion, androgenization enhanced pituitary TSHβ RIF, thyroid activation and liver Dio1 enzyme activity in Orx-MA, without elevating serum TSH as in Orx-YA rats. Estrogenization induced pituitary enlargement with no effect on pituitary TSHβ RIF, serum TSH or liver Dio1 activity. E also induced alterations in thyroid histology that indicate mild suppression of its functioning, and contributed to thyroid blood vessel enlargement in Orx-MA rats. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Deviation of the neurosporaxanthin pathway towards beta-carotene biosynthesis in Fusarium fujikuroi by a point mutation in the phytoene desaturase gene.

    PubMed

    Prado-Cabrero, Alfonso; Schaub, Patrick; Díaz-Sánchez, Violeta; Estrada, Alejandro F; Al-Babili, Salim; Avalos, Javier

    2009-08-01

    Carotenoids are widespread terpenoid pigments with applications in the food and feed industries. Upon illumination, the gibberellin-producing fungus Fusarium fujikuroi (Gibberella fujikuroi mating population C) develops an orange pigmentation caused by an accumulation of the carboxylic apocarotenoid neurosporaxanthin. The synthesis of this xanthophyll includes five desaturation steps presumed to be catalysed by the carB-encoded phytoene desaturase. In this study, we identified a yellow mutant (SF21) by mutagenesis of a carotenoid-overproducing strain. HPLC analyses indicated a specific impairment in the ability of SF21-CarB to perform the fifth desaturation, as implied by the accumulation of gamma-carotene and beta-carotene, which arise through four-step desaturation. Sequencing of the SF21 carB allele revealed a single mutation resulting in an exchange of a residue conserved in other five-step desaturases. Targeted carB allele replacement proved that this single mutation is the cause of the SF21 carotenoid pattern. In support, expression of SF21 CarB in engineered carotene-producing Escherichia coli strains demonstrated its reduced ability to catalyse the fifth desaturation step on both monocyclic and acyclic substrates. Further mutagenesis of SF21 led to the isolation of two mutants, SF73 and SF98, showing low desaturase activities, which mediated only two desaturation steps, resulting in accumulation of the intermediate zeta-carotene at low levels. Both strains contained an additional mutation affecting a CarB domain tentatively associated with carotenoid binding. SF21 exhibited higher carotenoid amounts than its precursor strain or the SF73 and SF98 mutants, although carotenogenic mRNA levels were similar in the four strains.

  10. Reproduction Does Not Adversely Affect Liver Mitochondrial Respiratory Function but Results in Lipid Peroxidation and Increased Antioxidants in House Mice.

    PubMed

    Mowry, Annelise V; Kavazis, Andreas N; Sirman, Aubrey E; Potts, Wayne K; Hood, Wendy R

    2016-01-01

    Reproduction is thought to come at a cost to longevity. Based on the assumption that increased energy expenditure during reproduction is associated with increased free-radical production by mitochondria, oxidative damage has been suggested to drive this trade-off. We examined the impact of reproduction on liver mitochondrial function by utilizing post-reproductive and non-reproductive house mice (Mus musculus) living under semi-natural conditions. The age-matched post-reproductive and non-reproductive groups were compared after the reproductive females returned to a non-reproductive state, so that both groups were in the same physiological state at the time the liver was collected. Despite increased oxidative damage (p = 0.05) and elevated CuZnSOD (p = 0.002) and catalase (p = 0.04) protein levels, reproduction had no negative impacts on the respiratory function of liver mitochondria. Specifically, in a post-reproductive, maintenance state the mitochondrial coupling (i.e., respiratory control ratio) of mouse livers show no negative impacts of reproduction. In fact, there was a trend (p = 0.059) to suggest increased maximal oxygen consumption by liver mitochondria during the ADP stimulated state (i.e., state 3) in post-reproduction. These findings suggest that oxidative damage may not impair mitochondrial respiratory function and question the role of mitochondria in the trade-off between reproduction and longevity. In addition, the findings highlight the importance of quantifying the respiratory function of mitochondria in addition to measuring oxidative damage.

  11. Improved γ-linolenic acid production in Mucor circinelloides by homologous overexpressing of delta-12 and delta-6 desaturases.

    PubMed

    Zhang, Yao; Luan, Xiao; Zhang, Huaiyuan; Garre, Victoriano; Song, Yuanda; Ratledge, Colin

    2017-06-21

    γ-Linolenic acid (GLA) is important because of its nutritional value and medicinal applications. Although the biosynthetic pathways of some plant and microbial GLA have been deciphered, current understanding of the correlation between desaturases and GLA synthesis in oleaginous fungi is incomplete. In previous work, we found that a large amount of oleic acid (OA) had not been converted to linoleic acid (LA) or GLA in Mucor circinelloides CBS 277.49, which may be due to inadequate activities of the delta-12 or delta-6 desaturases, and thus leading to the accumulation of OA and LA. Thus, it is necessary to explore the main contributing factor during the process of GLA biosynthesis in M. circinelloides. To enhance GLA production in M. circinelloides, homologous overexpression of delta-12 and two delta-6 desaturases (named delta-6-1 and delta-6-2, respectively) were analyzed. When delta-6 desaturase were overexpressed in M. circinelloides, up to 43% GLA was produced in the total fatty acids, and the yield of GLA reached 180 mg/l, which were, respectively, 38 and 33% higher than the control strain. These findings revealed that delta-6 desaturase (especially for delta-6-1 desaturase) plays an important role in GLA synthesis by M. circinelloides. The strain overexpressing delta-6-1 desaturase may have potential application in microbial GLA production.

  12. Current Metabolic Status Affects Urinary Liver-Type Fatty-Acid Binding Protein in Normoalbuminuric Patients With Type 2 Diabetes

    PubMed Central

    Ito, Hiroyuki; Yamashita, Hitomi; Nakashima, Mina; Takaki, Akifusa; Yukawa, Chiduko; Matsumoto, Suzuko; Omoto, Takashi; Shinozaki, Masahiro; Nishio, Shinya; Abe, Mariko; Antoku, Shinichi; Mifune, Mizuo; Togane, Michiko

    2017-01-01

    Background We aimed to study the association between urinary liver-type fatty acid-binding protein (L-FABP), a biomarker of tubulointerstitial injury, and the clinical characteristics of normoalbuminuric and albuminuric patients with type 2 diabetes in order to detect the factors affecting urinary L-FABP. Methods Urinary L-FABP levels were measured in 788 patients with type 2 diabetes and again in 666 patients at 6 months after the initial measurement. The association between the urinary L-FABP level and the clinical parameters was investigated in a retrospective cross-sectional study and a subsequent observation. Results The HbA1c (odds ratio (OR): 1.42; 95% confidence interval (CI): 1.11 - 1.79; P < 0.01), systolic blood pressure (OR: 1.03; 95% CI: 1.01 - 1.05; P < 0.01) levels and estimated glomerular filtration rate (OR: 0.98; 95% CI: 0.96 - 1.00; P = 0.01) were significantly associated with the high levels of urinary L-FABP (> 8.4 μg/gCr) in normoalbuminuric patients. However, a logistic regression analysis revealed that use of renin-angiotensin system (RAS) inhibitors (OR: 2.22; 95% CI: 1.16 - 4.89; P = 0.02), urinary albumin-to-creatinine ratio (ACR) (OR: 1.01; 95% CI: 1.00 - 1.01; P < 0.01) and serum HDL-cholesterol concentration (OR: 0.33; 95% CI: 0.11 - 0.89; P = 0.03) were significantly associated in albuminuric patients. In the follow-up observation, the change in urinary L-FABP was found to be significantly (P < 0.01) influenced by the change in the HbA1c level in both the normoalbuminuric and albuminuric patients. Conclusions High urinary L-FABP is associated with part of the current metabolic abnormalities, including high levels of HbA1c and systolic blood pressure among normoalbuminuric patients with type 2 diabetes. PMID:28270898

  13. 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.

    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 andmore » 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.« less

  14. 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. © 2016 Wiley Periodicals, Inc.

  15. 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 coriandermore » 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.« less

  16. Development of markers for Delta9-Stearoyl-ACP-Desaturase (SAD) to screen for cold acclimation

    USDA-ARS?s Scientific Manuscript database

    Delta 9-Stearoyl-acyl carrier protein (ACP) desaturase (SAD) is an important enzyme of fatty acid biosynthesis in higher plants. Located in the plastid stroma, SAD catalyzes the desaturation of stearoyl-ACP to oleyl-ACP. SAD plays a key role in determining the ratio of saturated fatty acids to unsat...

  17. Associations between plasma fatty acids, desaturase and elongase, and insulin resistance in children

    USDA-ARS?s Scientific Manuscript database

    Background and Objectives - Fatty acid profiles, desaturase (SCD-16, SCD018, D5D, D6D) and elongase (ELOVL6) enzyme activity have been associated with adiposity and metabolic disease. While this has been studied in adults, few studies have evaluated children. The objective of this study was to evalu...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  19. Changes in fatty acid composition in plant tissues expressing a mammalian delta9 desaturase.

    PubMed

    Moon, H; Hazebroek, J; Hildebrand, D F

    2000-05-01

    Plant tissues expressing a mammalian stearoyl-CoA delta9 desaturase were reported to accumulate delta9 hexadecenoic acid (16:1), normally very minor in most plant tissues. The transgenic plants were thoroughly analyzed for alterations of individual lipids in different subcellular sites. Western blot analysis indicated that the animal desaturase was targeted to the microsomes. The delta9 16:1 was incorporated into both the sn-1 and sn-2 positions of all the major membrane lipids tested, indicating that the endoplasmic reticulum acyltransferases do not exclude unsaturated C16 fatty acids from the sn-2 position. In addition to increases in monounsaturated and decreases in saturated fatty acids, accumulation of 16:1 was accompanied by a reduction in 18:3 in all the lipids tested except phosphatidylglycerol, and increases in 18:2 in phospholipids. Total C16 fatty acid content in the galactolipids of the transgenics was significantly higher than that in the control, but those in the phospholipids were unchanged. In transgenics, delta11 18:1 was detected in the sn-1 position of the lipids tested except phosphatidylinositol and phosphatidylserine. Introduction of the animal desaturase, controlled by a seed-specific phaseolin promoter, into soybean somatic embryo resulted in a significant reduction in saturated fatty acids. Such effects were greater in cotyledons than hypocotyl-radicles. This study demonstrated that the animal desaturase can be used to decrease the levels of saturated fatty acids in a crop plant.

  20. Metformin and/or Clomiphene Do Not Adversely Affect Liver or Renal Function in Women with Polycystic Ovary Syndrome

    PubMed Central

    Aubuchon, Mira; Kunselman, Allen R.; Schlaff, William D.; Diamond, Michael P.; Coutifaris, Christos; Carson, Sandra A.; Steinkampf, Michael P.; Carr, Bruce R.; McGovern, Peter G.; Cataldo, Nicholas A.; Gosman, Gabriella G.; Nestler, John E.; Myers, Evan R.

    2011-01-01

    Context: Nonalcoholic fatty liver disease is common to insulin-resistant states such as polycystic ovary syndrome (PCOS). Metformin (MET) is often used to treat PCOS but information is limited as to its effects on liver function. Objective: We sought to determine the effects of MET on serum hepatic parameters in PCOS patients. Design: This was a secondary analysis of a randomized, doubled-blind trial from 2002–2004. Setting: This multi-center clinical trial was conducted in academic centers. Patients: Six hundred twenty-six infertile women with PCOS with serum liver function parameters less than twice the upper limit of normal were included. Interventions: Clomiphene citrate (n = 209), MET (n = 208), or combined (n = 209) were given for up to 6 months. Main Outcome Measure: The percent change from baseline in renal and liver function between- and within-treatment arms was assessed. Results: Renal function improved in all treatment arms with significant decreases in serum blood urea nitrogen levels (range, −14.7 to −21.3%) as well as creatinine (−4.2 to −6.9%). There were similar decreases in liver transaminase levels in the clomiphene citrate and combined arms (−10% in bilirubin, −9 to −11% in transaminases) without significant changes in the MET arm. When categorizing baseline bilirubin, aspartate aminotransferase, and alanine aminotransferase into tertiles, there were significant within-treatment arm differences between the tertiles with the highest tertile having the largest decrease from baseline regardless of treatment arm. Conclusion: Women with PCOS can safely use metformin and clomiphene even in the setting of mildly abnormal liver function parameters, and both result in improved renal function. PMID:21832111

  1. Metformin and/or clomiphene do not adversely affect liver or renal function in women with polycystic ovary syndrome.

    PubMed

    Aubuchon, Mira; Kunselman, Allen R; Schlaff, William D; Diamond, Michael P; Coutifaris, Christos; Carson, Sandra A; Steinkampf, Michael P; Carr, Bruce R; McGovern, Peter G; Cataldo, Nicholas A; Gosman, Gabriella G; Nestler, John E; Myers, Evan R; Legro, Richard S

    2011-10-01

    Nonalcoholic fatty liver disease is common to insulin-resistant states such as polycystic ovary syndrome (PCOS). Metformin (MET) is often used to treat PCOS but information is limited as to its effects on liver function. We sought to determine the effects of MET on serum hepatic parameters in PCOS patients. This was a secondary analysis of a randomized, doubled-blind trial from 2002-2004. This multi-center clinical trial was conducted in academic centers. Six hundred twenty-six infertile women with PCOS with serum liver function parameters less than twice the upper limit of normal were included. Clomiphene citrate (n = 209), MET (n = 208), or combined (n = 209) were given for up to 6 months. The percent change from baseline in renal and liver function between- and within-treatment arms was assessed. Renal function improved in all treatment arms with significant decreases in serum blood urea nitrogen levels (range, -14.7 to -21.3%) as well as creatinine (-4.2 to -6.9%). There were similar decreases in liver transaminase levels in the clomiphene citrate and combined arms (-10% in bilirubin, -9 to -11% in transaminases) without significant changes in the MET arm. When categorizing baseline bilirubin, aspartate aminotransferase, and alanine aminotransferase into tertiles, there were significant within-treatment arm differences between the tertiles with the highest tertile having the largest decrease from baseline regardless of treatment arm. Women with PCOS can safely use metformin and clomiphene even in the setting of mildly abnormal liver function parameters, and both result in improved renal function.

  2. A Bacillus subtilis Gene Induced by Cold Shock Encodes a Membrane Phospholipid Desaturase

    PubMed Central

    Aguilar, Pablo S.; Cronan, John E.; de Mendoza, Diego

    1998-01-01

    Bacillus subtilis grown at 37°C synthesizes saturated fatty acids with only traces of unsaturated fatty acids (UFAs). However, when cultures growing at 37°C are transferred to 20°C, UFA synthesis is induced. We report the identification and characterization of the gene encoding the fatty acid desaturase of B. subtilis. This gene, called des, was isolated by complementation of Escherichia coli strains with mutations in either of two different genes of UFA synthesis. The des gene encodes a polypeptide of 352 amino acid residues containing the three conserved histidine cluster motifs and two putative membrane-spanning domains characteristic of the membrane-bound desaturases of plants and cyanobacteria. Expression of the des gene in E. coli resulted in desaturation of palmitic acid moieties of the membrane phospholipids to give the novel mono-UFA cis-5-hexadecenoic acid, indicating that the B. subtilis des gene product is a Δ5 acyl-lipid desaturase. The des gene was disrupted, and the resulting null mutant strains were unable to synthesize UFAs upon a shift to low growth temperatures. The des null mutant strain grew as well as its congenic parent at 20 or 37°C but showed severely reduced survival during stationary phase. Analysis of operon fusions in which the des promoter directed the synthesis of a lacZ reporter gene showed that des expression is repressed at 37°C, but a shift of cultures from 37 to 20°C resulted in a 10- to 15-fold increase in transcription. This is the first report of a membrane phospholipid desaturase in a nonphotosynthetic organism and the first direct evidence for cold induction of a desaturase. PMID:9555904

  3. A multivariate analysis of pre-, peri-, and post-transplant factors affecting outcome after pediatric liver transplantation.

    PubMed

    McDiarmid, Sue V; Anand, Ravinder; Martz, Karen; Millis, Michael J; Mazariegos, George

    2011-07-01

    The purpose of this study was to identify significant, independent factors that predicted 6 month patient and graft survival after pediatric liver transplantation. The Studies of Pediatric Liver Transplantation (SPLIT) is a multicenter database established in 1995, of currently more than 4000 US and Canadian children undergoing liver transplantation. Previous published analyses from this data have examined specific factors influencing outcome. This study analyzes a comprehensive range of factors that may influence outcome from the time of listing through the peri- and postoperative period. A total of 42 pre-, peri- and posttransplant variables evaluated in 2982 pediatric recipients of a first liver transplant registered in SPLIT significant at the univariate level were included in multivariate models. In the final model combining all baseline and posttransplant events, posttransplant complications had the highest relative risk of death or graft loss. Reoperation for any cause increased the risk for both patient and graft loss by 11 fold and reoperation exclusive of specific complications by 4 fold. Vascular thromboses, bowel perforation, septicemia, and retransplantation, each independently increased the risk of patient and graft loss by 3 to 4 fold. The only baseline factor with a similarly high relative risk for patient and graft loss was recipient in the intensive care unit (ICU) intubated at transplant. A significant center effect was also found but did not change the impact of the highly significant factors already identified. We conclude that the most significant factors predicting patient and graft loss at 6 months in children listed for transplant are posttransplant surgical complications.

  4. Atypical Antipsychotic Medications Increase Postprandial Triglyceride and Glucose Levels in Male Rats: Relationship with Stearoyl-CoA Desaturase Activity

    PubMed Central

    McNamara, Robert K.; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Cole-Strauss, Allyson; Lipton, Jack W.

    2011-01-01

    Recent preclinical and clinical evidence suggests that the stearoyl-CoA desaturase-1 (Scd1) enzyme plays a key role in the regulation of triglyceride (TG) biosynthesis and insulin sensitivity, and in vitro studies have found that antipsychotic medications up-regulate Scd1 mRNA expression. To investigate these effects in vivo, rats were treated with risperidone (1.5, 3, 6 mg/kg/d), paliperidone (1.5, 3, 6 mg/kg/d), olanzapine (2.5, 5, 10 mg/kg/d), quetiapine (5, 10, 20 mg/kg/d), haloperidol (1, 3 mg/kg/d) or vehicle through their drinking water for 40 d. Effects on liver Scd1 mRNA expression and an index of Scd1 activity (the plasma 18:1/18:0 ratio, ‘deaturation index’) were determined, as were postprandial plasma triglyceride (TG), glucose, insulin, and polyunsaturated fatty acid (PUFA) levels. All atypical antipsychotics increased the plasma 18:1/18:0 ratio, but not liver Scd1 mRNA expression, at doses found to also increase plasma TG levels. Among all rats (n=122), the plasma 18:1/18:0 ratio accounted for 56% of the variance in TG concentrations. The plasma 18:1/18:0 ratio was also positively associated with erythrocyte and heart membrane phospholipid 18:1n-9 composition. All antipsychotics except risperidone increased glucose levels at specific doses, and none of the antipsychotics significantly altered insulin levels. The plasma 18:1/18:0 ratio accounted for 20% of the variance in glucose levels. Plasma omega-3 and omega-6 PUFA levels were inversely correlated with the plasma 18:1/18:0 ratio and TG and glucose levels. These in vivo data demonstrate that different atypical antipsychotic medications increase the plasma 18:1/18:0 ratio in association with elevations in postprandial TG levels, and that concomitant elevations in PUFA biosynthesis oppose these effects. PMID:21474290

  5. Omega-3 Fatty Acid Deficiency Augments Risperidone-Induced Hepatic Steatosis in Rats: Positive Association with Stearoyl-CoA Desaturase

    PubMed Central

    McNamara, Robert K.; Magrisso, I. Jack; Hofacer, Rylon; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Benoit, Stephen C.

    2012-01-01

    Psychiatric patients frequently exhibit long-chain n-3 (LCn-3) fatty acid deficits and elevated triglyceride (TAG) production following chronic exposure to second generation antipsychotics (SGA). Emerging evidence suggests that SGAs and LCn-3 fatty acids have opposing effects on stearoyl-CoA desaturase-1 (SCD1), which plays a pivotal role in TAG biosynthesis. Here we evaluated whether low LCn-3 fatty acid status would augment elevations in rat liver and plasma TAG concentrations following chronic treatment with the SGA risperidone (RSP), and evaluated relationships with hepatic SCD1 expression and activity indices. In rats maintained on the n-3 fatty acid-fortified (control) diet, chronic RSP treatment significantly increased liver SCD1 mRNA and activity indices (18:1/18:0 and 16:1/16:0 ratios), and significantly increased liver, but not plasma, TAG concentrations. Rats maintained on the n-3 deficient diet exhibited significantly lower liver and erythrocyte LCn-3 fatty acid levels, and associated elevations in LCn-6/LCn-3 ratio. In n-3 deficient rats, RSP-induced elevations in liver SCD1 mRNA and activity indices (18:1/18:0 and 16:1/16:0 ratios) and liver and plasma TAG concentrations were significantly greater than those observed in RSP-treated controls. Plasma glucose levels were not altered by diet or RSP, and body weight was lower in RSP- and VEH-treated n-3 deficient rats. These preclinical data support the hypothesis that low n-3 fatty acid status exacerbates RSP-induced hepatic steatosis by augmenting SCD1 expression and activity. PMID:22750665

  6. Supplementation of Eurycoma longifolia Jack Extract for 6 Weeks Does Not Affect Urinary Testosterone: Epitestosterone Ratio, Liver and Renal Functions in Male Recreational Athletes

    PubMed Central

    Chen, Chee Keong; Mohamad, Wan Mohd Zahiruddin Wan; Ooi, Foong Kiew; Ismail, Shaiful Bahari; Abdullah, Mohamad Rusli; George, Annie

    2014-01-01

    Background: Eurycoma longifolia Jack (ElJ) has been shown to elevate serum testosterone and increased muscle strength in humans. This study investigated the effects of Physta® a standardized water extract of ElJ (400 mg/day for 6 weeks) on testosterone: epitestosterone (T:E) ratio, liver and renal functions in male recreational athletes. Methods: A total of 13 healthy male recreational athletes were recruited in this double blind, placebo-controlled, cross-over study. The participants were required to consume either 400 mg of ElJ or placebo daily for 6 weeks in the first supplementation regimen. Following a 3 week wash-out period, the participants were requested to consume the other supplement for another 6 weeks. Mid-stream urine samples and blood samples were collected prior to and after 6 weeks of supplementation with either ElJ or placebo. The urine samples were subsequently analyzed for T:E ratio while the blood samples were analyzed for liver and renal functions. Results: T:E ratio was not significantly different following 6 weeks supplementation of either ElJ or placebo compared with their respective baseline values. Similarly, there were no significant changes in both the liver and renal functions tests following the supplementation of ElJ. Conclusions: Supplementation of ElJ i.e. Physta® at a dosage of 400 mg/day for 6 weeks did not affect the urinary T:E ratio and hence will not breach any doping policies of the International Olympic Committee for administration of exogenous testosterone or its precursor. In addition, the supplementation of ElJ at this dosage and duration was safe as it did adversely affect the liver and renal functions. PMID:25013692

  7. Overexpression of Peroxiredoxin 4 Affects Intestinal Function in a Dietary Mouse Model of Nonalcoholic Fatty Liver Disease

    PubMed Central

    Noguchi, Hirotsugu; Mazaki, Yuichi; Kurahashi, Toshihiro; Izumi, Hiroto; Wang, Ke-Yong; Guo, Xin; Uramoto, Hidetaka; Kohno, Kimitoshi; Taniguchi, Hatsumi; Tanaka, Yoshiya; Fujii, Junichi; Sasaguri, Yasuyuki; Tanimoto, Akihide; Nakayama, Toshiyuki

    2016-01-01

    Background Accumulating evidence has shown that methionine- and choline-deficient high fat (MCD+HF) diet induces the development of nonalcoholic fatty liver disease (NAFLD), in which elevated reactive oxygen species play a crucial role. We have reported that peroxiredoxin 4 (PRDX4), a unique secretory member of the PRDX antioxidant family, protects against NAFLD progression. However, the detailed mechanism and potential effects on the intestinal function still remain unclear. Methods & Results Two weeks after feeding mice a MCD+HF diet, the livers of human PRDX4 transgenic (Tg) mice exhibited significant suppression in the development of NAFLD compared with wild-type (WT) mice. The serum thiobarbituric acid reactive substances levels were significantly lower in Tg mice. In contrast, the Tg small intestine with PRDX4 overexpression showed more suppressed shortening of total length and villi height, and more accumulation of lipid in the jejunum, along with lower levels of dihydroethidium binding. The enterocytes exhibited fewer apoptotic but more proliferating cells, and inflammation was reduced in the mucosa. Furthermore, the small intestine of Tg mice had significantly higher expression of cholesterol absorption-regulatory factors, including liver X receptor-α, but lower expression of microsomal triglyceride-transfer protein. Conclusion Our present data provide the first evidence of the beneficial effects of PRDX4 on intestinal function in the reduction of the severity of NAFLD, by ameliorating oxidative stress-induced local and systemic injury. We can suggest that both liver and intestine are spared, to some degree, by the antioxidant properties of PRDX4. PMID:27035833

  8. Clinical trial with traditional Chinese medicine intervention ''tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment'' for chronic hepatitis B-associated liver failure.

    PubMed

    Li, Han-Min; Ye, Zhi-Hua; Zhang, Jun; Gao, Xiang; Chen, Yan-Ming; Yao, Xin; Gu, Jian-Xun; Zhan, Lei; Ji, Yang; Xu, Jian-Liang; Zeng, Ying-He; Yang, Fan; Xiao, Lin; Sheng, Guo-Guang; Xin, Wei; Long, Qi; Zhu, Qing-Jing; Shi, Zhao-Hong; Ruan, Lian-Guo; Yang, Jia-Yao; Li, Chang-Chun; Wu, Hong-Bin; Chen, Sheng-Duo; Luo, Xin-La

    2014-12-28

    To study the clinical efficacy of traditional Chinese medicine (TCM) intervention "tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment" ("TTK") for treating liver failure due to chronic hepatitis B. We designed the study as a randomized controlled clinical trial. Registration number of Chinese Clinical Trial Registry is ChiCTR-TRC-12002961. A total of 144 patients with liver failure due to infection with chronic hepatitis B virus were enrolled in this randomized controlled clinical study. Participants were randomly assigned to the following three groups: (1) a modern medicine control group (MMC group, 36 patients); (2) a "tonifying qi and detoxification" ("TQD") group (72 patients); and (3) a "tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment" ("TTK") group (36 patients). Patients in the MMC group received general internal medicine treatment; patients in the "TQD" group were given a TCM formula "tonifying qi and detoxification" and general internal medicine treatment; patients in the "TTK" group were given a TCM formula of "TTK" and general internal medicine treatment. All participants were treated for 8 wk and then followed at 48 wk following their final treatment. The primary efficacy end point was the patient fatality rate in each group. Measurements of various virological and biochemical indicators served as secondary endpoints. The one-way analysis of variance and the t-test were used to compare patient outcomes in the different treatment groups. At the 48-wk post-treatment time point, the patient fatality rates in the MMC, "TQD", and "TTK" groups were 51.61%, 35.38%, and 16.67%, respectively, and the differences between groups were statistically significant (P < 0.05). However, there were no significant differences in the levels of hepatitis B virus DNA or prothrombin activity among the three groups (P > 0.05). Patients in the "TTK

  9. A single mutation in the castor Delta9-18:0-desaturase changes reaction partitioning from desaturation to oxidase chemistry.

    PubMed

    Guy, Jodie E; Abreu, Isabel A; Moche, Martin; Lindqvist, Ylva; Whittle, Edward; Shanklin, John

    2006-11-14

    Sequence analysis of the diiron cluster-containing soluble desaturases suggests they are unrelated to other diiron enzymes; however, structural alignment of the core four-helix bundle of desaturases to other diiron enzymes reveals a conserved iron binding motif with similar spacing in all enzymes of this structural class, implying a common evolutionary ancestry. Detailed structural comparison of the castor desaturase with that of a peroxidase, rubrerythrin, shows remarkable conservation of both identity and geometry of residues surrounding the diiron center, with the exception of residue 199. Position 199 is occupied by a threonine in the castor desaturase, but the equivalent position in rubrerythrin contains a glutamic acid. We previously hypothesized that a carboxylate in this location facilitates oxidase chemistry in rubrerythrin by the close apposition of a residue capable of facilitating proton transfer to the activated oxygen (in a hydrophobic cavity adjacent to the diiron center based on the crystal structure of the oxygen-binding mimic azide). Here we report that desaturase mutant T199D binds substrate but its desaturase activity decreases by approximately 2 x 10(3)-fold. However, it shows a >31-fold increase in peroxide-dependent oxidase activity with respect to WT desaturase, as monitored by single-turnover stopped-flow spectrometry. A 2.65-A crystal structure of T199D reveals active-site geometry remarkably similar to that of rubrerythrin, consistent with its enhanced function as an oxidase enzyme. That a single amino acid substitution can switch reactivity from desaturation to oxidation provides experimental support for the hypothesis that the desaturase evolved from an ancestral oxidase enzyme.

  10. A single mutation in the castor Δ9-18:0-desaturase changes reaction partitioning from desaturation to oxidase chemistry

    PubMed Central

    Guy, Jodie E.; Abreu, Isabel A.; Moche, Martin; Lindqvist, Ylva; Whittle, Edward; Shanklin, John

    2006-01-01

    Sequence analysis of the diiron cluster-containing soluble desaturases suggests they are unrelated to other diiron enzymes; however, structural alignment of the core four-helix bundle of desaturases to other diiron enzymes reveals a conserved iron binding motif with similar spacing in all enzymes of this structural class, implying a common evolutionary ancestry. Detailed structural comparison of the castor desaturase with that of a peroxidase, rubrerythrin, shows remarkable conservation of both identity and geometry of residues surrounding the diiron center, with the exception of residue 199. Position 199 is occupied by a threonine in the castor desaturase, but the equivalent position in rubrerythrin contains a glutamic acid. We previously hypothesized that a carboxylate in this location facilitates oxidase chemistry in rubrerythrin by the close apposition of a residue capable of facilitating proton transfer to the activated oxygen (in a hydrophobic cavity adjacent to the diiron center based on the crystal structure of the oxygen-binding mimic azide). Here we report that desaturase mutant T199D binds substrate but its desaturase activity decreases by ≈2 × 103-fold. However, it shows a >31-fold increase in peroxide-dependent oxidase activity with respect to WT desaturase, as monitored by single-turnover stopped-flow spectrometry. A 2.65-Å crystal structure of T199D reveals active-site geometry remarkably similar to that of rubrerythrin, consistent with its enhanced function as an oxidase enzyme. That a single amino acid substitution can switch reactivity from desaturation to oxidation provides experimental support for the hypothesis that the desaturase evolved from an ancestral oxidase enzyme. PMID:17088542

  11. Cadmium affects the mitochondrial viability and the acid soluble thiols concentration in liver, kidney, heart and gills of Ancistrus brevifilis (Eigenmann, 1920)

    PubMed Central

    Velasquez-Vottelerd, P.; Anton, Y.; Salazar-Lugo, R.

    2015-01-01

    The freshwater fish Ancistrus brevifilis, which is found in Venezuelan rivers, is considered a potential sentinel fish in ecotoxicological studies. The cadmium (Cd) effect on the mitochondrial viability (MV) and acid soluble thiols levels (AST) in A. brevifilis tissues (liver, kidney, heart, and gill) was evaluated. Forty-two fish with similar sizes and weights were randomly selected, of which 7 fish (with their respective replicate) were exposed for 7 and 30 days to a Cd sublethal concentration (0.1 mg.l-1). We determined the MV through a Janus Green B colorimetric assay and we obtained the concentration of AST by Ellman’s method. Mitochondrial viability decreased in fish exposed to Cd for 30 days with the liver being the most affected tissue. We also detected a significant decrease in AST levels was in fishes exposed to Cd for 7 days in liver and kidney tissues; these results suggests that AST levels are elevated in some tissues may act as cytoprotective and adaptive alternative mechanism related to the ROS detoxification, maintenance redox status and mitochondrial viability. Organ-specifics variations were observed in both assays. We conclude that the Cd exposure effect on AST levels and MV, vary across fish tissues and is related to the exposure duration, the molecule dynamics in different tissues, the organism and environmental conditions. PMID:26623384

  12. Association of polyunsaturated fatty acids in breast milk with fatty acid desaturase gene polymorphisms among Chinese lactating mothers.

    PubMed

    Ding, Zhen; Liu, Guo-Liang; Li, Xiang; Chen, Xue-Yan; Wu, Yi-Xia; Cui, Can-Can; Zhang, Xi; Yang, Guang; Xie, Lin

    2016-06-01

    The fatty acid desaturase (FADS) controls polyunsaturated fatty acid (PUFA) synthesis in human tissues and breast milk. Evaluate the influence of 10 single nucleotide polymorphisms (SNPs) and various haplotypes in the FADS gene cluster (FADS1, FADS2, FADS3) on PUFA concentration in the breast milk of 209 healthy Chinese women. PUFA concentrations were measured in breast milk using gas chromatography and genotyping was performed using the Sequenom Mass Array system. A SNP (rs1535) and 2-locus haplotypes (rs3834458-rs1535, rs1535-rs174575) in the FADS2 gene were associated with concentrations of γ-linoleic acid (GLA) and arachidonic acid (AA) in breast milk. Likewise, in the FADS1 gene, a 2-locus constructed haplotype (rs174547-rs174553) also affected GLA and AA concentration (P<0.05 for all). Minor allele carriers of the SNP and haplotypes described above had lower concentrations of GLA and AA. In the FADS2 gene, the 3-locus haplotype rs3834458-rs1535-rs174575, significantly affected concentrations of GLA but not AA. Pairwise comparison showed that individuals major homozygous for the SNP rs1000778 in the FADS3 gene had lower concentrations of ALA and linoleic acid (LA) in their breast milk. Polymorphisms in the FADS gene cluster influence PUFA concentrations in the breast milk of Chinese Han lactating women. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 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).

  14. Donation After Circulatory Death for Liver Transplantation: A Meta-Analysis on the Location of Life Support Withdrawal Affecting Outcomes.

    PubMed

    Cao, Yiming; Shahrestani, Sara; Chew, Hong Chee; Crawford, Michael; Macdonald, Peter Simon; Laurence, Jerome; Hawthorne, Wayne John; Dhital, Kumud; Pleass, Henry

    2016-07-01

    Liver transplantation using donation after circulatory death (DCD) donors is associated with inferior outcomes compared to donation after brain death (DBD). Prolonged donor warm ischemic time has been identified as the key factor responsible for this difference. Various aspects of the donor life support withdrawal procedure, including location of withdrawal and administration of antemortem heparin, are thought to play important roles in mitigating the effects of warm ischemia. However, a systematic exploration of these factors is important for more confident integration of these practices into a standard DCD protocol. Medline, EMBASE, and Cochrane libraries were systematically searched and 23 relevant studies identified for analysis. Donation after circulatory death recipients were stratified according to location of life support withdrawal (intensive care unit or operating theater) and use of antemortem heparin. Donation after circulatory death recipients had comparable 1-year patient survival to DBD recipients if the location of withdrawal of life support was the operating theater, but not if the location was the intensive care unit. Likewise, the inferior 1-year graft survival and higher incidence of ischemic cholangiopathy of DCD compared with DBD recipients were improved by withdrawal in operating theater, although higher rates of ischemic cholangiopathy and worse graft survival were still observed in DCD recipients. Furthermore, administering heparin before withdrawal of life support reduced the incidence of primary nonfunction of the allograft. Our evidence suggests that withdrawal in the operating theater and premortem heparin administration improve DCD liver transplant outcomes, thus allowing for the most effective usage of these valuable organs.

  15. 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.

  16. Disruption of a horizontally transferred phytoene desaturase abolishes carotenoid accumulation and diapause in Tetranychus urticae

    PubMed Central

    Bryon, Astrid; Kurlovs, Andre H.; Greenhalgh, Robert; Riga, Maria; Grbić, Miodrag; Tirry, Luc; Osakabe, Masahiro; Vontas, John; Clark, Richard M.; Van Leeuwen, Thomas

    2017-01-01

    Carotenoids underlie many of the vibrant yellow, orange, and red colors in animals, and are involved in processes ranging from vision to protection from stresses. Most animals acquire carotenoids from their diets because de novo synthesis of carotenoids is primarily limited to plants and some bacteria and fungi. Recently, sequencing projects in aphids and adelgids, spider mites, and gall midges identified genes with homology to fungal sequences encoding de novo carotenoid biosynthetic proteins like phytoene desaturase. The finding of horizontal gene transfers of carotenoid biosynthetic genes to three arthropod lineages was unprecedented; however, the relevance of the transfers for the arthropods that acquired them has remained largely speculative, which is especially true for spider mites that feed on plant cell contents, a known source of carotenoids. Pigmentation in spider mites results solely from carotenoids. Using a combination of genetic approaches, we show that mutations in a single horizontally transferred phytoene desaturase result in complete albinism in the two-spotted spider mite, Tetranychus urticae, as well as in the citrus red mite, Panonychus citri. Further, we show that phytoene desaturase activity is essential for photoperiodic induction of diapause in an overwintering strain of T. urticae, consistent with a role for this enzyme in provisioning provitamin A carotenoids required for light perception. Carotenoid biosynthetic genes of fungal origin have therefore enabled some mites to forgo dietary carotenoids, with endogenous synthesis underlying their intense pigmentation and ability to enter diapause, a key to the global distribution of major spider mite pests of agriculture. PMID:28674017

  17. Functional characterization of two microsomal fatty acid desaturases from Jatropha curcas L.

    PubMed

    Wu, Pingzhi; Zhang, Sheng; Zhang, Lin; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

    2013-10-15

    Linoleic acid (LA, C18:2) and α-linolenic acid (ALA, C18:3) are polyunsaturated fatty acids (PUFAs) and major storage compounds in plant seed oils. Microsomal ω-6 and ω-3 fatty acid (FA) desaturases catalyze the synthesis of seed oil LA and ALA, respectively. Jatropha curcas L. seed oils contain large proportions of LA, but very little ALA. In this study, two microsomal desaturase genes, named JcFAD2 and JcFAD3, were isolated from J. curcas. Both deduced amino acid sequences possessed eight histidines shown to be essential for desaturases activity, and contained motif in the C-terminal for endoplasmic reticulum localization. Heterologous expression in Saccharomyces cerevisiae and Arabidopsis thaliana confirmed that the isolated JcFAD2 and JcFAD3 proteins could catalyze LA and ALA synthesis, respectively. The results indicate that JcFAD2 and JcFAD3 are functional in controlling PUFA contents of seed oils and could be exploited in the genetic engineering of J. curcas, and potentially other plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  18. Novel Genes Encoding Hexadecanoic Acid Δ6-Desaturase Activity in a Rhodococcus sp.

    PubMed

    Araki, Hiroyuki; Hagihara, Hiroshi; Takigawa, Hirofumi; Tsujino, Yukiharu; Ozaki, Katsuya

    2016-11-01

    cis-6-Hexadecenoic acid, a major component of human sebaceous lipids, is involved in the defense mechanism against Staphylococcus aureus infection in healthy skin and closely related to atopic dermatitis. Previously, Koike et al. (Biosci Biotechnol Biochem 64:1064-1066, 2000) reported that a mutant strain of Rhodococcus sp. produced cis-6-hexadecenoate derivatives from palmitate alkyl esters. From the mutant Rhodococcus strain, we identified and sequenced two open reading frames present in an amplified 5.7-kb region; these open reading frames encoded tandemly repeated Δ6-desaturase-like genes, Rdes1 and Rdes2. A phylogenetic tree indicated that Rdes1 and Rdes2 were different from previously known Δ6-desaturase genes, and that they formed a new cluster. Rdes1 and Rdes2 were each introduced into vectors and then expressed separately in Escherichia coli, and the fatty acid composition of the transformed cells was analyzed by gas chromatography and mass spectrometry. The amount of cis-6-hexadecenoic acid was significantly higher in Rdes1- or Rdes2-transformed E. coli cells (twofold and threefold, respectively) than in vector-only control cells. These results showed that cis-6-hexadecenoic acid was produced in E. coli cells by the rhodococcal Δ6-desaturase-like proteins.

  19. Liver Transplant

    MedlinePlus

    ... Liver Function Tests Clinical Trials Liver Transplant FAQs Medical Terminology Diseases of the Liver Alagille Syndrome Alcohol-Related ... the Liver The Progression of Liver Disease FAQs Medical Terminology HOW YOU CAN HELP Sponsorship Ways to Give ...

  20. Source of metabolizable energy affects gene transcription in metabolic pathways in adipose and liver tissue of nonlactating, pregnant dairy cows.

    PubMed

    Crookenden, M A; Mandok, K S; Grala, T M; Phyn, C V C; Kay, J K; Greenwood, S L; Roche, J R

    2015-02-01

    The objective of this experiment was to determine if transcript abundance of genes involved in metabolic pathways in adipose and liver tissue could provide some explanation for the low efficiency with which ME in autumn pasture is used for BW gain. Nonlactating, pregnant (208 ± 19 d of gestation or approximately 75 d precalving) dairy cows (n = 90) were randomly allocated to either a control diet (i.e., offered fresh autumn pasture to maintenance requirements: 0.55 MJ ME/kg of measured metabolic BW [BW0.75] per day) or, in addition to the control diet, 1 of 2 supplement amounts (2.5 and 5.0 kg DM/d) of autumn pasture or 1 of 4 supplementary feeds (i.e., a control and 2 levels of feeding for each of 5 feeds: 11 groups of cows). Along with autumn pasture, evaluated feeds included spring pasture silage, maize silage, maize grain, and palm kernel expeller. Adipose and liver tissues were biopsied in wk 4 of the experiment and transcript abundance of genes involved in metabolic pathways associated with energy metabolism, lipolysis, and lipogenesis was determined. Additional feed, irrespective of type, increased BW gain (P < 0.01) and this effect was reflected in the expression of genes in adipose and liver tissue. However, autumn pasture had lower energy-use efficiency than the other feeds. Genes involved in both lipogenesis (ACACA, THRSP, GPAM, GPD1, and LPL) and lipolysis (PNPLA2) were upregulated (P < 0.05) in adipose tissue in response to increased ME intake/kilogram BW0.75. Hepatic expression of APOA1 decreased and that of APOB increased (P < 0.05) in cows offered maize grain and maize silage (i.e., starch-containing feeds). In comparison, pasture-fed cows demonstrated a degree of uncoupling of the somatotropic axis, with lower hepatic transcript abundance of both GHR1A and IGF-1 compared with cows offered any of the other 4 feeds. Changes to gene transcription indicate a possible molecular mechanism for the poor BW gain evident in ruminants consuming autumn

  1. Alterations by peroxisome proliferators of acyl composition of hepatic phosphatidylcholine in rats, mice and guinea-pigs. Role of stearoyl-CoA desaturase.

    PubMed Central

    Kawashima, Y; Hirose, A; Kozuka, H

    1986-01-01

    Rats, mice and guinea-pigs were administered p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). The treatments of rats and mice with either clofibric acid or tiadenol increased markedly the activities of stearoyl-CoA desaturase, palmitoyl-CoA chain elongation, 1-acylglycerophosphate (1-acyl-GP) acyltransferase and 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, but not 2-acylglycerophosphocholine (2-acyl-GPC) acyltransferase in liver microsomes. The treatment of guinea-pigs with clofibric acid did not cause any change in the activities of these enzymes. The treatment of guinea-pigs with tiadenol caused a slight, but significant, increase in the activities of 1-acyl-GP acyltransferase and 1-acyl-GPC acyltransferase. The treatment of rats and mice with either clofibric acid or tiadenol increased markedly the proportion of 18:1 and decreased greatly the proportion of 18:0 in liver microsomal phosphatidylcholine. However, there is a considerable difference in the effects of the two peroxisome proliferators on the composition of polyunsaturated fatty acids in phosphatidylcholine between rats and mice. The treatment of guinea-pigs with either of the two peroxisome proliferators caused no change in acyl composition of phosphatidylcholine. The possible role of stearoyl-CoA desaturation in the regulation of acyl composition of phosphatidylcholine was discussed. PMID:2874791

  2. Loss of stearoyl-CoA desaturase 1 rescues cardiac function in obese leptin-deficient mice.

    PubMed

    Dobrzyn, Pawel; Dobrzyn, Agnieszka; Miyazaki, Makoto; Ntambi, James M

    2010-08-01

    The heart of leptin-deficient ob/ob mice is characterized by pathologic left ventricular hypertrophy along with elevated triglyceride (TG) content, increased stearoyl-CoA desaturase (SCD) activity, and increased myocyte apoptosis. In the present study, using an ob/ob;SCD1(-/-) mouse model, we tested the hypothesis that lack of SCD1 could improve steatosis and left ventricle (LV) function in leptin deficiency. We show that disruption of the SCD1 gene improves cardiac function in ob/ob mice by correcting systolic and diastolic dysfunction without affecting levels of plasma TG and FFA. The improvement is associated with reduced expression of genes involved in FA transport and lipid synthesis in the heart, as well as reduction in cardiac FFA, diacylglycerol, TG, and ceramide levels. The rate of FA beta-oxidation is also significantly lower in the heart of ob/ob;SCD1(-/-) mice compared with ob/ob controls. Moreover, SCD1 deficiency reduces cardiac apoptosis in ob/ob mice due to increased expression of antiapoptotic factor Bcl-2 and inhibition of inducible nitric oxide synthase and caspase-3 activities. Reduction in myocardial lipid accumulation and inhibition of apoptosis appear to be one of the main mechanisms responsible for improved LV function in ob/ob mice caused by SCD1 deficiency.

  3. Systemic Down-Regulation of Delta-9 Desaturase Promotes Muscle Oxidative Metabolism and Accelerates Muscle Function Recovery following Nerve Injury

    PubMed Central

    Henriques, Alexandre; Lequeu, Thiebault; Rene, Frederique; Bindler, Françoise; Dirrig-Grosch, Sylvie; Oudart, Hugues; Palamiuc, Lavinia; Metz-Boutigue, Marie-Helene; Dupuis, Luc; Marchioni, Eric; Gonzalez De Aguilar, Jose-Luis; Loeffler, Jean-Philippe

    2013-01-01

    The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS). Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles. PMID:23785402

  4. Skeletal muscle mass to visceral fat area ratio is an important determinant affecting hepatic conditions of non-alcoholic fatty liver disease.

    PubMed

    Shida, Takashi; Akiyama, Kentaro; Oh, Sechang; Sawai, Akemi; Isobe, Tomonori; Okamoto, Yoshikazu; Ishige, Kazunori; Mizokami, Yuji; Yamagata, Kenji; Onizawa, Kojiro; Tanaka, Hironori; Iijima, Hiroko; Shoda, Junichi

    2018-04-01

    Not only obesity but also sarcopenia is associated with NAFLD. The influence of altered body composition on the pathophysiology of NAFLD has not been fully elucidated. The aim of this study is to determine whether skeletal muscle mass to visceral fat area ratio (SV ratio) affects NAFLD pathophysiology. A total of 472 subjects were enrolled. The association between SV ratio and NAFLD pathophysiological factors was assessed in a cross-sectional nature by stratification analysis. When the SV ratio was stratified by quartiles (Q 1 -Q 4 ), the SV ratio showed a negative relationship with the degree of body mass index, HOMA-IR, and liver stiffness (Q 1 , 8.9 ± 7.5 kPa, mean ± standard deviation; Q 2 , 7.5 ± 6.2; Q 3 , 5.8 ± 3.7; Q 4 , 5.0 ± 1.9) and steatosis (Q 1 , 282 ± 57 dB/m; Q 2 , 278 ± 58; Q 3 , 253 ± 57; Q 4 , 200 ± 42) measured by transient elastography. Levels of leptin and biochemical markers of liver cell damage, liver fibrosis, inflammation and oxidative stress, and hepatocyte apoptosis were significantly higher in subjects in Q 1 than in those in Q 2 , Q 3 , or Q 4 . Moreover, fat contents in femoral muscles were significantly higher in subjects in Q 1 and the change was associated with weakened muscle strength. In logistic regression analysis, NAFLD subjects with the decreased SV ratio were likely to have an increased risk of moderate-to-severe steatosis and that of advanced fibrosis. Decreased muscle mass coupled with increased visceral fat mass is closely associated with an increased risk for exacerbating NAFLD pathophysiology.

  5. Biochemical changes in rat liver after 18.5 days of spaceflight (41566)

    NASA Technical Reports Server (NTRS)

    Abraham, S.; Lin, C.Y.; Volkmann, C. M.; Klein, H. P.

    1983-01-01

    The effect of weightlessness on liver metabolism was investigated using tissue from rats flown in earth orbit for 18.5 days on the Soviet Cosmos 936 biosatellite and the changes in the activities of 28 carbohydrate and lipid enzymes were determined. The activities of two enzymes, palmitoyl-CoA desaturase and lactate dehydrogenase, increased, while the activities of five, glycogen phosphorylase, 6-phosphogluconate dehydrogenase, both acyltransferases which act on alpha-glycerolphosphate and diglycerides, and and aconitate hydratase decreased. The other enzyme activities were found to be unchanged. In addition, increased levels of liver glycogen and palmitoleate were detected which probably resulted from the lowered glycogen phosphorylase and increased palmitoyl-CoA desaturase activities, respectively, in those animals that experienced weightlessness. All of the changes observed in the rats after 18.5 days of spaceflight disappear by 25 days after the flight.

  6. Characterization and comparison of fatty acyl Delta6 desaturase cDNAs from freshwater and marine teleost fish species.

    PubMed

    Zheng, X; Seiliez, I; Hastings, N; Tocher, D R; Panserat, S; Dickson, C A; Bergot, P; Teale, A J

    2004-10-01

    Fish are the most important dietary source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), that have particularly important roles in human nutrition reflecting their roles in critical physiological processes. The objective of the study described here was to clone, functionally characterize and compare expressed fatty acid desaturase genes involved in the production of EPA and DHA in freshwater and marine teleost fish species. Putative fatty acid desaturase cDNAs were isolated and cloned from common carp (Cyprinus carpio) and turbot (Psetta maximus). The enzymic activities of the products of these cDNAs, together with those of cDNAs previously cloned from rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata), were determined by heterologous expression in the yeast Saccharomyces cerevisiae. The carp and turbot desaturase cDNAs included open reading frames (ORFs) of 1335 and 1338 base pairs, respectively, specifying proteins of 444 and 445 amino acids. The protein sequences possessed all the characteristic features of microsomal fatty acid desaturases, including three histidine boxes, two transmembrane regions, and N-terminal cytochrome b(5) domains containing the haem-binding motif, HPGG. Functional expression showed all four fish cDNAs encode basically unifunctional Delta6 fatty acid desaturase enzymes responsible for the first and rate-limiting step in the biosynthesis of HUFA from 18:3n-3 and 18:2n-6. All the fish desaturases were more active towards the n-3 substrate with 59.5%, 31.5%, 23.1% and 7.0% of 18:3n-3 being converted to 18:4n-3 in the case of turbot, trout, sea bream and carp, respectively. The enzymes also showed very low, probably physiologically insignificant, levels of Delta5 desaturase activity, but none of the products showed Delta4 desaturase activity. The cloning and characterization of desaturases from these fish is an important advance, as they are species in which

  7. Substantial replacement of lactose with fat in a high-lactose milk replacer diet increases liver fat accumulation but does not affect insulin sensitivity in veal calves.

    PubMed

    Pantophlet, A J; Gerrits, W J J; Vonk, R J; van den Borne, J J G C

    2016-12-01

    In veal calves, the major portion of digestible energy intake originates from milk replacer (MR), with lactose and fat contributing approximately 45 and 35%, respectively. In veal calves older than 4 mo, prolonged high intakes of MR may lead to problems with glucose homeostasis and insulin sensitivity, ultimately resulting in sustained insulin resistance, hepatic steatosis, and impaired animal performance. The contribution of each of the dietary energy sources (lactose and fat) to deteriorated glucose homeostasis and insulin resistance is currently unknown. Therefore, an experiment was designed to compare the effects of a high-lactose and a high-fat MR on glucose homeostasis and insulin sensitivity in veal calves. Sixteen male Holstein-Friesian calves (120±2.8kg of BW) were assigned to either a high-lactose (HL) or a high-fat (HF) MR for 13 consecutive weeks. After at least 7 wk of adaptation, whole-body insulin sensitivity and insulin secretion were assessed by euglycemic-hyperinsulinemic and hyperglycemic clamps, respectively. Postprandial blood samples were collected to assess glucose, insulin, and triglyceride responses to feeding, and 24-h urine was collected to quantify urinary glucose excretion. At the end of the trial, liver and muscle biopsies were taken to assess triglyceride contents in these tissues. Long-term exposure of calves to HF or HL MR did not affect whole-body insulin sensitivity (averaging 4.2±0.5×10 -2 [(mg/kg∙min)/(μU/mL)]) and insulin secretion. Responses to feeding were greater for plasma glucose and tended to be greater for plasma insulin in HL calves than in HF calves. Urinary glucose excretion was substantially higher in HL calves (75±13g/d) than in HF calves (21±6g/d). Muscle triglyceride content was not affected by treatment and averaged 4.5±0.6g/kg, but liver triglyceride content was higher in HF calves (16.4±0.9g/kg) than in HL calves (11.2±0.7g/kg), indicating increased hepatic fat accumulation. We conclude that

  8. Sexual dimorphism of liver metastasis by murine pancreatic neuroendocrine tumors is affected by expression of complement C5.

    PubMed

    Contractor, Tanupriya; Kobayashi, Shinta; da Silva, Edaise; Clausen, Richard; Chan, Chang; Vosburgh, Evan; Tang, Laura H; Levine, Arnold J; Harris, Chris R

    2016-05-24

    In a mouse model for neuroendocrine tumors of the pancreas (PanNETs), liver metastasis occurred at a higher frequency in males. Male mice also had higher serum and intratumoral levels of the innate immunity protein complement C5. In mice that lost the ability to express complement C5, there was a lower frequency of metastasis, and males no longer had a higher frequency of metastasis than females. Treatment with PMX53, a small molecule antagonist of C5aR1/CD88, the receptor for complement C5a, also reduced metastasis. Mice lacking a functional gene for complement C5 had smaller primary tumors, which were less invasive and lacked the CD68+ macrophages that have previously been associated with metastasis in this type of tumor. This is the first report of a gene that causes sexual dimorphism of metastasis in a mouse model. In the human disease, which also shows sexual dimorphism for metastasis, clinically advanced tumors expressed more complement C5 than less advanced tumors.

  9. 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.

  10. Biosynthesis of 10,12-dienoic fatty acids by a bifunctional Delta11 desaturase in Spodoptera littoralis.

    PubMed

    Serra, Montserrat; Piña, Benjami; Bujons, Jordi; Camps, Francisco; Fabriàs, Gemma

    2006-08-01

    In the biosynthetic pathway of Spodoptera littoralis sex pheromone, (E,E)-10,12-tetradecadienoic acid is produced from (Z)-11-tetradecenoic acid by desaturation and concomitant migration of the precursor double bond. With the aim of identifying the enzyme involved in this biotransformation, yeast Deltaelo1/Deltaole mutants, which are both elongase 1 and Delta9 desaturase-deficient, were transformed with the S. littoralis Delta11 desaturase gene using a Cu+2 inducible expression vector. The transformants produced a recombinant polyhistidine-tagged Delta11 desaturase that could be detected by immunoblotting from cell lysates. Lipid analysis revealed that besides producing large quantities of C11-monounsaturated fatty acids, mainly (Z)-11-hexadecenoic acid, (E,E)-10,12-tetradecadienoic acid and minor amounts of (E,Z)-10,12-hexadecadienoic acid were also produced, as well as very low quantities of another tetradecadienoate, which was tentatively identified as the (E,Z)-10,12-tetradecadienoic isomer. None of these dienes was detected with the Delta11 desaturase gene of Trichoplusia ni, which does not produce conjugated dienes as pheromone components. We conclude that the Delta11 desaturase of S. littoralis is a bifunctional enzyme with both Delta11 and Delta10,12 desaturation activities. The relationship between the substrate structure and the stereochemical outcome of the reaction is discussed.

  11. Perfluorodecanoic acid enhances the formation of oleic acid in rat liver.

    PubMed Central

    Yamamoto, A; Kawashima, Y

    1997-01-01

    The feeding of perfluorodecanoic acid (PFDA) to male rats at a dietary concentration of 0.005% (w/w) for 7 days resulted in a marked increase in the activity of microsomal stearoyl-CoA desaturation in the liver. This increase in the overall desaturation activity was due to the induction of terminal desaturase among the components comprising the desaturation system. In contrast, PFDA inhibited desaturation in vitro, seemingly due to interference with electron transport through the desaturation system. Accordingly, PFDA can be an inducer and also an inhibitor of delta9-desaturation. PFDA feeding enhanced the conversion of radioactive stearic acid into oleic acid in the liver in vivo, indicating that the induction of delta9-desaturase by PFDA functions in vivo. PFDA feeding increased the mass of octadecenoic acid (C18:1) in the liver and the proportion of C18:1 in microsomal lipid. A highly significant linear correlation existed between the microsomal desaturase activity and the proportion of C18:1 in microsomal lipid when compared using rats in five different physiological states: control, PFDA-fed, p-chlorophenoxyisobutyric acid (clofibric acid)-fed, starved and starved/refed. These results suggest that the increase in the hepatic level of C18:1 caused by feeding of PFDA to rats can be explained by the common concept of regulation, i.e. the hepatic level of C18:1 is under the control of delta9-desaturase. The dietary administration of PFDA also increased the content of cytochrome P-450 and the activity of 7-ethoxycoumarin O-de-ethylase in the liver. PMID:9230124

  12. [Behaviour of the LAP (leucine-amino-peptidase) in the serum of blood in subjects affected of cirrhosis of the liver in stage ascitical (author's transl)].

    PubMed

    Pace, M; Fernandes, D

    1980-12-01

    The AA. have studied behaviour of the LAP (leucine-amino-peptidase) in the serum of blood in subjects affected of cirrhosis of the liver in stage ascitical, of cause toxic-alcoholic excluding about of the casuistry the cirrhosis of the another cause and the cirrhosis that are compled white an obstruction in and extrahepatic standard biliary cirrhosis 1 degree e 2 degree. After the exposition of the casuistry in the registred normality of the test (seric-LAP) in some cases of hepatic-alcoholic cirrhosis, the AA. concluded considering the LAP an indicator only of the obstruction in and extra-hepatic, consistent with hepatic-organ well operating; do not be a secure test to follow development of a chronic hepatitis of any kind, even if in the hepatic disease is present an infiltration and an overturning of the hepatic-lobule, like it is normally in the hepatic alcoholic diseases.

  13. Vitamin B1 Deficiency Does not Affect the Liver Concentrations of the Other Seven Kinds of B-Group Vitamins in Rats

    PubMed Central

    Shibata, Katsumi; Shimizu, Atsushi; Fukuwatari, Tsutomu

    2013-01-01

    We aimed to determine the effects of vitamin B1 deficiency on vitamin contents of urine, liver, and blood. In the current study, rats were divided into 3 groups (n = 5, each group): the first was freely fed a complete diet (ad lib-fed control group); the second freely fed a vitamin B1-free diet (vitamin B1 deficient group); and the third pair-fed a complete diet with the same amounts of the vitamin B1 deficient group (pair-fed control group). The experimental period was for 15 days. The blood concentrations of vitamin B2, PLP, vitamin B12, folic acid, and biotin were lower in the pair-fed control than in the ad lib-fed control and those of nicotinamide and pantothenic acid were the same. We conclude that Vitamin B1 deficiency did not affect concentrations of the other B-group vitamins. PMID:23935367

  14. Atypical antipsychotic medications increase postprandial triglyceride and glucose levels in male rats: relationship with stearoyl-CoA desaturase activity.

    PubMed

    McNamara, Robert K; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Cole-Strauss, Allyson; Lipton, Jack W

    2011-06-01

    Recent preclinical and clinical evidence suggests that the stearoyl-CoA desaturase-1 (Scd1) enzyme plays a key role in the regulation of triglyceride (TG) biosynthesis and insulin sensitivity, and in vitro studies have found that antipsychotic medications up-regulate Scd1 mRNA expression. To investigate these effects in vivo, rats were treated with risperidone (1.5, 3, and 6mg/kg/d), paliperidone (1.5, 3, and 6mg/kg/d), olanzapine (2.5, 5, and 10mg/kg/d), quetiapine (5, 10, and 20mg/kg/d), haloperidol (1, and 3mg/kg/d) or vehicle through their drinking water for 40days. Effects on liver Scd1 mRNA expression and an index of Scd1 activity (the plasma 18:1/18:0 ratio, 'desaturation index') were determined, as were postprandial plasma triglyceride (TG), glucose, insulin, and polyunsaturated fatty acid (PUFA) levels. All atypical antipsychotics increased the plasma 18:1/18:0 ratio, but not liver Scd1 mRNA expression, at doses found to also increase plasma TG levels. Among all rats (n=122), the plasma 18:1/18:0 ratio accounted for 56% of the variance in TG concentrations. The plasma 18:1/18:0 ratio was also positively associated with erythrocyte and heart membrane phospholipid 18:1n-9 composition. All antipsychotics except risperidone increased glucose levels at specific doses, and none of the antipsychotics significantly altered insulin levels. The plasma 18:1/18:0 ratio accounted for 20% of the variance in glucose levels. Plasma omega-3 and omega-6 PUFA levels were inversely correlated with the plasma 18:1/18:0 ratio and TG and glucose levels. These in vivo data demonstrate that different atypical antipsychotic medications increase the plasma 18:1/18:0 ratio in association with elevations in postprandial TG and glucose levels, and that concomitant elevations in PUFA biosynthesis oppose these effects. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Influence of oilseed supplement ranging in n-6/n-3 ratio on fatty acid composition and Δ5-, Δ6-desaturase protein expression in steer muscles.

    PubMed

    Turner, T D; Mitchell, A; Duynisveld, J; Pickova, J; Doran, O; McNiven, M A

    2012-12-01

    This study investigated effects of roasted or extruded oilseed supplementation ranging in n-6/n-3 ratios from 0.3 to 5.0 on the fatty acid composition and expression of delta-5 desaturase (Δ5d) and Δ6-desaturase (Δ6d) protein in commercial steer cheek (m. masseter) and diaphragm (pars costalis diaphragmatis) muscles. In general, the n-6/n-3 ratio of the diet had a subsequent effect on the muscle n-6/n-3 ratio (P < 0.05), with muscle 18:2n-6 and 18:3n-3 content relating to proportion of dietary soya bean and linseed (P < 0.01). Compared with canola, pure linseed and soya bean diets reduced 14:1c-9 and 16:1c-9 (P < 0.05) but increased 18:1t-11 and c-9,t-11 conjugated linoleic acid (CLA) content (P < 0.01). Oilseed processing had a minor influence but extruded oilseeds increase 18:1t-11 and c-9,t-11 CLA compared with roasted (P < 0.05). Polar lipid 18:3n-3 and n-3 long-chain polyunsaturated fatty acid (LC, ⩾20 carbons PUFA) derivative content increased in relation to dietary linseed supplementation in the diaphragm (P < 0.01), whereas only 18:3n-3 was increased in the cheek (P < 0.01). Protein expression did not differ between diets; however, in each muscle the Δ5d protein expression had a stronger association with the desaturase products rather than the precursors. The relationship between Δ5d protein expression and the muscle LC n-6/n-3 ratio was negative in both muscles (P < 0.05). The relationship between Δ6d protein expression and the LC n-6/n-3 ratio was positive in the cheek (P < 0.001) and negative in the diaphragm (P < 0.05). In conclusion, diet n-6/n-3 ratio affected muscle 18:2n-6 and 18:3n-3 deposition, whereas the Δ5d and Δ6d protein expression had some influence on the polar lipid LC-PUFA profile. Results reaffirm that processed oilseeds can be used to increase the proportion of fatty acids potentially beneficial for human health, by influencing the formation of LC-PUFA and reducing the n-6/n-3 ratio.

  16. The combination of blueberry juice and probiotics reduces apoptosis of alcoholic fatty liver of mice by affecting SIRT1 pathway.

    PubMed

    Zhu, Juanjuan; Ren, Tingting; Zhou, Mingyu; Cheng, Mingliang

    2016-01-01

    To explore the effects of the combination of blueberry juice and probiotics on the apoptosis of alcoholic fatty liver disease (AFLD). Healthy C57BL/6J mice were used in the control group (CG). AFLD mice models were established with Lieber-DeCarli ethanol diet and evenly assigned to six groups with different treatments: MG (model), SI (SIRT1 [sirtuin type 1] small interfering RNA [siRNA]), BJ (blueberry juice), BJSI (blueberry juice and SIRT1 siRNA), BJP (blueberry juice and probiotics), and BJPSI (blueberry juice, probiotics, and SIRT1 siRNA). Hepatic tissue was observed using hematoxylin and eosin (HE) and Oil Red O (ORO) staining. Biochemical indexes of the blood serum were analyzed. The levels of SIRT1, caspase-3, forkhead box protein O1 (FOXO1), FasL (tumor necrosis factor ligand superfamily member 6), BAX, and Bcl-2 were measured by reverse transcription-polymerase chain reaction and Western blotting. HE and ORO staining showed that the hepatocytes were heavily destroyed with large lipid droplets in MG and SI groups, while the severity was reduced in the CG, BJ, and BJP groups (P<0.05). The levels of superoxide dismutase (SOD), reduced glutathione (GSH), and high-density lipoprotein-cholesterol (HDL-C) were increased in BJ and BJP groups when compared with the model group (P<0.05). In contrast, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total triglycerides (TGs), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and malondialdehyde (MDA) were lower in BJ and BJP groups than in the model group (P<0.05). The level of SIRT1 was increased, while the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 were decreased in CG, BJ, and BJP groups (P<0.05). Meanwhile, SIRT1 silence resulted in increase of the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2. The combination of blueberry juice and probiotics reduces apoptosis in AFLD by

  17. Percutaneous Radiofrequency Ablation of Colorectal Cancer Liver Metastases: Factors Affecting Outcomes—A 10-year Experience at a Single Center

    PubMed Central

    Shady, Waleed; Petre, Elena N.; Gonen, Mithat; Erinjeri, Joseph P.; Brown, Karen T.; Covey, Anne M.; Alago, William; Durack, Jeremy C.; Maybody, Majid; Brody, Lynn A.; Siegelbaum, Robert H.; D’Angelica, Michael I.; Jarnagin, William R.; Solomon, Stephen B.; Kemeny, Nancy E.

    2016-01-01

    Purpose To identify predictors of oncologic outcomes after percutaneous radiofrequency ablation (RFA) of colorectal cancer liver metastases (CLMs) and to describe and evaluate a modified clinical risk score (CRS) adapted for ablation as a patient stratification and prognostic tool. Materials and Methods This study consisted of a HIPAA-compliant institutional review board–approved retrospective review of data in 162 patients with 233 CLMs treated with percutaneous RFA between December 2002 and December 2012. Contrast material–enhanced CT was used to assess technique effectiveness 4–8 weeks after RFA. Patients were followed up with contrast-enhanced CT every 2–4 months. Overall survival (OS) and local tumor progression–free survival (LTPFS) were calculated from the time of RFA by using the Kaplan-Meier method. Log-rank tests and Cox regression models were used for univariate and multivariate analysis to identify predictors of outcomes. Results Technique effectiveness was 94% (218 of 233). Median LTPFS was 26 months. At univariate analysis, predictors of shorter LTPFS were tumor size greater than 3 cm (P < .001), ablation margin size of 5 mm or less (P < .001), high modified CRS (P = .009), male sex (P = .03), and no history of prior hepatectomy (P = .04) or hepatic arterial infusion chemotherapy (P = .01). At multivariate analysis, only tumor size greater than 3 cm (P = .01) and margin size of 5 mm or less (P < .001) were independent predictors of shorter LTPFS. Median and 5-year OS were 36 months and 31%. At univariate analysis, predictors of shorter OS were tumor size larger than 3 cm (P = .005), carcinoembryonic antigen level greater than 30 ng/mL (P = .003), high modified CRS (P = .02), and extrahepatic disease (EHD) (P < .001). At multivariate analysis, tumor size greater than 3 cm (P = .006) and more than one site of EHD (P < .001) were independent predictors of shorter OS. Conclusion Tumor size of less than 3 cm and ablation margins greater than 5 mm

  18. The combination of blueberry juice and probiotics reduces apoptosis of alcoholic fatty liver of mice by affecting SIRT1 pathway

    PubMed Central

    Zhu, Juanjuan; Ren, Tingting; Zhou, Mingyu; Cheng, Mingliang

    2016-01-01

    Purpose To explore the effects of the combination of blueberry juice and probiotics on the apoptosis of alcoholic fatty liver disease (AFLD). Methods Healthy C57BL/6J mice were used in the control group (CG). AFLD mice models were established with Lieber–DeCarli ethanol diet and evenly assigned to six groups with different treatments: MG (model), SI (SIRT1 [sirtuin type 1] small interfering RNA [siRNA]), BJ (blueberry juice), BJSI (blueberry juice and SIRT1 siRNA), BJP (blueberry juice and probiotics), and BJPSI (blueberry juice, probiotics, and SIRT1 siRNA). Hepatic tissue was observed using hematoxylin and eosin (HE) and Oil Red O (ORO) staining. Biochemical indexes of the blood serum were analyzed. The levels of SIRT1, caspase-3, forkhead box protein O1 (FOXO1), FasL (tumor necrosis factor ligand superfamily member 6), BAX, and Bcl-2 were measured by reverse transcription-polymerase chain reaction and Western blotting. Results HE and ORO staining showed that the hepatocytes were heavily destroyed with large lipid droplets in MG and SI groups, while the severity was reduced in the CG, BJ, and BJP groups (P<0.05). The levels of superoxide dismutase (SOD), reduced glutathione (GSH), and high-density lipoprotein-cholesterol (HDL-C) were increased in BJ and BJP groups when compared with the model group (P<0.05). In contrast, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total triglycerides (TGs), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and malondialdehyde (MDA) were lower in BJ and BJP groups than in the model group (P<0.05). The level of SIRT1 was increased, while the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 were decreased in CG, BJ, and BJP groups (P<0.05). Meanwhile, SIRT1 silence resulted in increase of the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2. Conclusion The combination of blueberry juice and

  19. 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

  20. [Desaturases of fatty acids (FADS) and their physiological and clinical implication].

    PubMed

    Žák, Aleš; Slabý, Adolf; Tvrzická, Eva; Jáchymová, Marie; Macášek, Jaroslav; Vecka, Marek; Zeman, Miroslav; Staňková, Barbora

    States associated with insulin resistance, as overweight/obesity, type 2 diabetes mellitus (DM2), cardiovascular diseases (CVD), some cancers and neuropsychiatric diseases are characterized with a decrease of long-chain polyunsaturated fatty acids (LC-PUFA) levels. Amounts of LC-PUFA depend on the exogenous intake of their precursors [linoleic (LA) and α-linolenic acid (ALA)] and by rate of their metabolism, which is influenced by activities of enzymes, such as Δ6-desaturase (D6D, FADS2), D5D, FADS1, elongases (Elovl2, -5, 6).Altered activities of D5D/D6D were described in plenty of diseases, e.g. neuropsychiatric (depressive disorders, bipolar disorder, dementia), metabolic (obesity, metabolic syndrome, DM2) and cardiovascular diseases (arterial hypertension, coronary heart disease), inflammatory states and allergy (Crohns disease, atopic eczema) or some malignancies. Similar results were obtained in studies dealing with the associations between genotypes/haplotypes of FADS1/FADS2 and above mentioned diseases, or interactions of dietary intake of LA and ALA on one hand and of the polymorphisms of minor allels of FADS1/FADS2, usually characterized by lower activities, on the other hand.The decrease of the desaturases activities leads to decreased concentrations of products with concomitant increased concentrations of substrates. Associations of some SNP FADS with coronary heart disease, concentrations of plasma lipids, oxidative stress, glucose homeostasis, and inflammatory reaction, were described. Experimental studies on animal models and occurrence of rare diseases, associated with missing or with marked fall activities of D5D/D6D emphasized the significance of desaturases for healthy development of organism as well as for pathogenesis of some disease.

  1. Altered fatty acid metabolism and reduced stearoyl-coenzyme a desaturase activity in asthma.

    PubMed

    Rodriguez-Perez, N; Schiavi, E; Frei, R; Ferstl, R; Wawrzyniak, P; Smolinska, S; Sokolowska, M; Sievi, N A; Kohler, M; Schmid-Grendelmeier, P; Michalovich, D; Simpson, K D; Hessel, E M; Jutel, M; Martin-Fontecha, M; Palomares, O; Akdis, C A; O'Mahony, L

    2017-11-01

    Fatty acids and lipid mediator signaling play an important role in the pathogenesis of asthma, yet this area remains largely underexplored. The aims of this study were (i) to examine fatty acid levels and their metabolism in obese and nonobese asthma patients and (ii) to determine the functional effects of altered fatty acid metabolism in experimental models. Medium- and long-chain fatty acid levels were quantified in serum from 161 human volunteers by LC/MS. Changes in stearoyl-coenzyme A desaturase (SCD) expression and activity were evaluated in the ovalbumin (OVA) and house dust mite (HDM) murine models. Primary human bronchial epithelial cells from asthma patients and controls were evaluated for SCD expression and activity. The serum desaturation index (an indirect measure of SCD) was significantly reduced in nonobese asthma patients and in the OVA murine model. SCD1 gene expression was significantly reduced within the lungs following OVA or HDM challenge. Inhibition of SCD in mice promoted airway hyper-responsiveness. SCD1 expression was suppressed in bronchial epithelial cells from asthma patients. IL-4 and IL-13 reduced epithelial cell SCD1 expression. Inhibition of SCD reduced surfactant protein C expression and suppressed rhinovirus-induced IP-10 secretion, which was associated with increased viral titers. This is the first study to demonstrate decreased fatty acid desaturase activity in humans with asthma. Experimental models in mice and human epithelial cells suggest that inhibition of desaturase activity leads to airway hyper-responsiveness and reduced antiviral defense. SCD may represent a new target for therapeutic intervention in asthma patients. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  2. Genetic variation of six desaturase genes in flax and their impact on fatty acid composition.

    PubMed

    Thambugala, Dinushika; Duguid, Scott; Loewen, Evelyn; Rowland, Gordon; Booker, Helen; You, Frank M; Cloutier, Sylvie

    2013-10-01

    Flax (Linum usitatissimum L.) is one of the richest plant sources of omega-3 fatty acids praised for their health benefits. In this study, the extent of the genetic variability of genes encoding stearoyl-ACP desaturase (SAD), and fatty acid desaturase 2 (FAD2) and 3 (FAD3) was determined by sequencing the six paralogous genes from 120 flax accessions representing a broad range of germplasm including some EMS mutant lines. A total of 6 alleles for sad1 and sad2, 21 for fad2a, 5 for fad2b, 15 for fad3a and 18 for fad3b were identified. Deduced amino acid sequences of the alleles predicted 4, 2, 3, 4, 6 and 7 isoforms, respectively. Allele frequencies varied greatly across genes. Fad3a, with 110 SNPs and 19 indels, and fad3b, with 50 SNPs and 5 indels, showed the highest levels of genetic variations. While most of the SNPs and all the indels were silent mutations, both genes carried nonsense SNP mutations resulting in premature stop codons, a feature not observed in sad and fad2 genes. Some alleles and isoforms discovered in induced mutant lines were absent in the natural germplasm. Correlation of these genotypic data with fatty acid composition data of 120 flax accessions phenotyped in six field experiments revealed statistically significant effects of some of the SAD and FAD isoforms on fatty acid composition, oil content and iodine value. The novel allelic variants and isoforms identified for the six desaturases will be a resource for the development of oilseed flax with unique and useful fatty acid profiles.

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

    PubMed

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

    2016-06-06

    Mimicry illustrates the power of selection to produce phenotypic convergence in biology [1]. A striking example is the imitation of female insects by plants that are pollinated by sexual deception of males of the same insect species [2-4]. This involves mimicry of visual, tactile, and chemical signals of females [2-7], especially their sex pheromones [8-11]. 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 [11-13]. A difference in alkene double-bond positions is responsible for reproductive isolation between O. exaltata and closely related species, such as O. sphegodes [13-16]. 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. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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

    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

  5. Half-of-the-Sites Reactivity of the Castor Δ9-18:0-Acyl Carrier Protein Desaturase.

    PubMed

    Liu, Qin; Chai, Jin; Moche, Martin; Guy, Jodie; Lindqvist, Ylva; Shanklin, John

    2015-09-01

    Fatty acid desaturases regulate the unsaturation status of cellular lipids. They comprise two distinct evolutionary lineages, a soluble class found in the plastids of higher plants and an integral membrane class found in plants, yeast (Saccharomyces cerevisiae), animals, and bacteria. Both classes exhibit a dimeric quaternary structure. Here, we test the functional significance of dimeric organization of the soluble castor Δ9-18:0-acyl carrier protein desaturase, specifically, the hypothesis that the enzyme uses an alternating subunit half-of-the-sites reactivity mechanism whereby substrate binding to one subunit is coordinated with product release from the other subunit. Using a fluorescence resonance energy transfer assay, we demonstrated that dimers stably associate at concentrations typical of desaturase assays. An active site mutant T104K/S202E, designed to occlude the substrate binding cavity, was expressed, purified, and its properties validated by x-ray crystallography, size exclusion chromatography, and activity assay. Heterodimers comprising distinctly tagged wild-type and inactive mutant subunits were purified at 1:1 stoichiometry. Despite having only one-half the number of active sites, purified heterodimers exhibit equivalent activity to wild-type homodimers, consistent with half-of-the-sites reactivity. However, because multiple rounds of turnover were observed, we conclude that substrate binding to one subunit is not required to facilitate product release from the second subunit. The observed half-of-the-sites reactivity could potentially buffer desaturase activity from oxidative inactivation. That soluble desaturases require only one active subunit per dimer for full activity represents a mechanistic difference from the membrane class of desaturases such as the Δ9-acyl-CoA, Ole1p, from yeast, which requires two catalytically competent subunits for activity. © 2015 American Society of Plant Biologists. All Rights Reserved.

  6. Half-of-the-Sites Reactivity of the Castor Δ9-18:0-Acyl Carrier Protein Desaturase1[OPEN

    PubMed Central

    Liu, Qin; Chai, Jin; Moche, Martin; Guy, Jodie; Lindqvist, Ylva; Shanklin, John

    2015-01-01

    Fatty acid desaturases regulate the unsaturation status of cellular lipids. They comprise two distinct evolutionary lineages, a soluble class found in the plastids of higher plants and an integral membrane class found in plants, yeast (Saccharomyces cerevisiae), animals, and bacteria. Both classes exhibit a dimeric quaternary structure. Here, we test the functional significance of dimeric organization of the soluble castor Δ9-18:0-acyl carrier protein desaturase, specifically, the hypothesis that the enzyme uses an alternating subunit half-of-the-sites reactivity mechanism whereby substrate binding to one subunit is coordinated with product release from the other subunit. Using a fluorescence resonance energy transfer assay, we demonstrated that dimers stably associate at concentrations typical of desaturase assays. An active site mutant T104K/S202E, designed to occlude the substrate binding cavity, was expressed, purified, and its properties validated by x-ray crystallography, size exclusion chromatography, and activity assay. Heterodimers comprising distinctly tagged wild-type and inactive mutant subunits were purified at 1:1 stoichiometry. Despite having only one-half the number of active sites, purified heterodimers exhibit equivalent activity to wild-type homodimers, consistent with half-of-the-sites reactivity. However, because multiple rounds of turnover were observed, we conclude that substrate binding to one subunit is not required to facilitate product release from the second subunit. The observed half-of-the-sites reactivity could potentially buffer desaturase activity from oxidative inactivation. That soluble desaturases require only one active subunit per dimer for full activity represents a mechanistic difference from the membrane class of desaturases such as the Δ9-acyl-CoA, Ole1p, from yeast, which requires two catalytically competent subunits for activity. PMID:26224800

  7. Periodic acid‑Schiff staining method for function detection of liver cells is affected by 2% horse serum in induction medium.

    PubMed

    Hui, Hui; Ma, Wenjun; Cui, Jiejie; Gong, Mengjia; Wang, Yi; Zhang, Yuanyuan; He, Tongchuan; Bi, Yang; He, Yun

    2017-12-01

    Developing a thorough understanding of experimental methods of hepatic differentiation in hepatic progenitor cells (HPCs) should expand the knowledge of hepatocyte induction in vitro and may help to develop cell transplantation therapies for the clinical usage of HPCs in liver diseases. A previous induction method effectively induced differentiation and metabolic abilities in HPCs. Periodic acid‑Schiff (PAS) staining is used to identify glycogen synthesis and hepatocyte function; however, this method failed to detect induced hepatocytes. The present study aimed to investigate the possible factors affecting the previous confusing results of PAS staining. Removal of single induction factors, including dexamethasone, hepatic growth factor and fibroblast growth factor 4 from the induction media did not restore PAS staining, whereas replacement of 2% horse serum (HS) with 10% fetal bovine serum (FBS) significantly increased the number of PAS positive cells. Following 12 days of basal induction, replacing the induction medium with media containing 10% FBS for 12‑72 h significantly improved PAS staining, but did not influence indocyanine green uptake. Furthermore, incubation in induction medium with 10% FBS following 12 days of normal induction did not affect the expression of hepatic markers and mature function of HPCs. Therefore, the present study suggested that 2% HS in the induction medium did not affect the hepatic function of induced cells, but did affect glycogen storage, whereas replacement of medium with 10% FBS in advance of PAS staining may restore the failure of PAS staining in low serum concentrations of induced hepatocytes.

  8. 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.

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

    SciTech Connect

    Schluter, P.M.; Shanklin, J.; Xu, S.

    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 asmore » 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.« less

  10. 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

  11. Bioinformatics analysis of the ς-carotene desaturase gene in cabbage (Brassica oleracea var. capitata)

    NASA Astrophysics Data System (ADS)

    Sun, Bo; Zheng, Aihong; Jiang, Min; Xue, Shengling; Zhang, Fen; Tang, Haoru

    2018-04-01

    ς-carotene desaturase (ZDS) is an important enzyme in carotenoid biosynthesis. Here, the Brassica oleracea var. capitata ZDS (BocZDS) gene sequences were obtained from Brassica database (BRAD), and preformed for bioinformatics analysis. The BocZDS gene mapped to Scaffold000363, and contains an open reading frame of 1,686 bp that encodes a 561-amino acid protein with a calculated molecular mass of 62.00 kD and an isoelectric point (pI) of 8.2. Subcellular localization predicted the BocZDS gene was in the chloroplast. The conserved domain of the BocZDS protein is PLN02487, indicating that it belongs the member of zeta-carotene desaturase. Homology analysis indicates that the ZDS protein is apparently conserved during plant evolution and is most closely related to B. oleracea var. oleracea, B. napus, and B. rapa. The findings of the present study provide a molecular basis for the elucidation of ZDS gene function in cabbage.

  12. Regulation of yeast fatty acid desaturase in response to iron deficiency.

    PubMed

    Romero, Antonia María; Jordá, Tania; Rozès, Nicolas; Martínez-Pastor, María Teresa; Puig, Sergi

    2018-06-01

    Unsaturated fatty acids (UFA) are essential components of phospholipids that greatly contribute to the biophysical properties of cellular membranes. Biosynthesis of UFAs relies on a conserved family of iron-dependent fatty acid desaturases, whose representative in the model yeast Saccharomyces cerevisiae is Ole1. OLE1 expression is tightly regulated to adapt UFA biosynthesis and lipid bilayer properties to changes in temperature, and in UFA or oxygen availability. Despite iron deficiency being the most extended nutritional disorder worldwide, very little is known about the mechanisms and the biological relevance of fatty acid desaturases regulation in response to iron starvation. In this report, we show that endoplasmic reticulum-anchored transcription factor Mga2 activates OLE1 transcription in response to nutritional and genetic iron deficiencies. Cells lacking MGA2 display low UFA levels and do not grow under iron-limited conditions, unless UFAs are supplemented or OLE1 is overexpressed. The proteasome, E3 ubiquitin ligase Rsp5 and the Cdc48 Npl4/Ufd1 complex are required for OLE1 activation during iron depletion. Interestingly, Mga2 also activates the transcription of its own mRNA in response to iron deficiency, hypoxia, low temperature and low UFAs. MGA2 up-regulation contributes to increase OLE1 expression in these situations. These results reveal the mechanism of OLE1 regulation when iron is scarce and identify the MGA2 auto-regulation as a potential activation strategy in multiple stresses. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. 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

  14. 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

  15. A More Desirable Balanced Polyunsaturated Fatty Acid Composition Achieved by Heterologous Expression of Δ15/Δ4 Desaturases in Mammalian Cells

    PubMed Central

    Zhu, Guiming; Ou, Qin; Zhang, Tao; Jiang, Xudong; Sun, Guozhi; Zhang, Ning; Wang, Kunfu; Fang, Heng; Wang, Mingfu; Sun, Jie; Ge, Tangdong

    2013-01-01

    Arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are the most biologically active polyunsaturated fatty acids, but their biosyntheses in mammals are very limited. The biosynthesis of DHA is the most difficult, because this undergoes the Sprecher pathway–a further elongation step from docosapentaenoic acid (DPA), a Δ6-desaturase acting on a C24 fatty acid substrate followed by a peroxisomal chain shortening step. This paper reports the successful heterologous expression of two non-mammalian genes (with modification of codon usage), coding for Euglena gracilis Δ4-desaturase and Siganus canaliculatus Δ4-desaturase respectively, in mammalian cells (HEK293 cell line). Both of the Δ4-desaturases can efficiently function, directly converting DPA into DHA. Moreover, the cooperation of the E. gracilis Δ4-desaturase with C. elegans Δ15-desaturase (able to convert a number of n-6 PUFAs to their corresponding n-3 PUFAs) in transgenic HEK293 cells made a more desirable fatty acid composition – a drastically reduced n-6/n-3 PUFAs ratio and a high level of DHA as well as EPA and ARA. Our findings provide a basis for potential applications of the gene constructs for expression of Δ15/Δ4-desaturases in transgenic livestock to produce such a fatty acid profile in the related products, which certainly will bring benefit to human health. PMID:24391980

  16. The level of orally ingested vitamin C affected the expression of vitamin C transporters and vitamin C accumulation in the livers of ODS rats.

    PubMed

    Sone, Yasuko; Ueta, Etsuko; Kodama, Satoru; Sannoumaru, Yasuko; Miyake, Noriko; Sone, Hirohito; Fujiwara, Yoko; Otsuka, Yuzuru; Kondo, Kazuo; Inagaki, Masahiro; Namba, Eiji; Kurata, Tadao; Suzuki, Emiko

    2011-01-01

    We investigated the effects of vitamin C administration on vitamin C-specific transporters in ODS/ShiJcl-od/od rat livers. The vitamin C-specific transporter levels increased in the livers of the rats not administered vitamin C and decreased in the livers of those administered vitamin C at 100 mg/d, indicating that these transporter levels can be influenced by the amount of vitamin C administered.

  17. Cloning and characterization of unusual fatty acid desaturases from Anemone leveillei: identification of an acyl-coenzyme A C20 Delta5-desaturase responsible for the synthesis of sciadonic acid.

    PubMed

    Sayanova, Olga; Haslam, Richard; Venegas Caleron, Monica; Napier, Johnathan A

    2007-05-01

    The seed oil of Anemone leveillei contains significant amounts of sciadonic acid (20:3Delta(5,11,14); SA), an unusual non-methylene-interrupted fatty acid with pharmaceutical potential similar to arachidonic acid. Two candidate cDNAs (AL10 and AL21) for the C(20) Delta(5cis)-desaturase from developing seeds of A. leveillei were functionally characterized in transgenic Arabidopsis (Arabidopsis thaliana) plants. The open reading frames of both Delta(5)-desaturases showed some similarity to presumptive acyl-coenzyme A (CoA) desaturases found in animals and plants. When expressed in transgenic Arabidopsis, AL21 showed a broad range of substrate specificity, utilizing both saturated (16:0 and 18:0) and unsaturated (18:2, n-6 and 18:3, n-3) substrates. In contrast, AL10 did not show any activity in wild-type Arabidopsis. Coexpression of AL10 or AL21 with a C(18) Delta(9)-elongase in transgenic Arabidopsis plants resulted in the production of SA and juniperonic fatty acid (20:4Delta(5,11,14,17)). Thus, AL10 acted only on C(20) polyunsaturated fatty acids in a manner analogous to "front-end" desaturases. However, neither AL10 nor AL21 contain the cytochrome b(5) domain normally present in this class of enzymes. Acyl-CoA profiling of transgenic Arabidopsis plants and developing A. leveillei seeds revealed significant accumulation of Delta(5)-unsaturated fatty acids as acyl-CoAs compared to the accumulation of these fatty acids in total lipids. Positional analysis of triacylglycerols of A. leveillei seeds showed that Delta(5)-desaturated fatty acids were present in both sn-2 and sn-1 + sn-3 positions, although the majority of 16:1Delta(5), 18:1Delta(5), and SA was present at the sn-2 position. Our data provide biochemical evidence for the A. leveillei Delta(5)-desaturases using acyl-CoA substrates.

  18. Contribution of two ζ-carotene desaturases to the poly-cis desaturation pathway in the cyanobacterium Nostoc PCC 7120.

    PubMed

    Breitenbach, Jürgen; Bruns, Marius; Sandmann, Gerhard

    2013-07-01

    The presence of two completely unrelated ζ-carotene desaturases CrtQa and CrtQb in some Nostoc strains is unique. CrtQb is the ζ-carotene desaturase, which was acquired by almost all cyanobacteria. The additional CrtQa can be regarded as an evolutionary relict of the CrtI desaturase present in non-photosynthetic bacteria. By reconstruction of the carotene desaturation pathway, we showed that both enzymes from Nostoc PCC 7120 were active. However, they differed in their preferred utilization of ζ-carotene Z isomers. CrtQa converted ζ-carotene isomers that were poorly metabolized by CrtQb. In this respect, CrtQa complemented the reactions of CrtQb, which is an advantage avoiding dead ends in the poly-cis desaturation pathway. In addition to ζ-carotene desaturation, CrtQa still possesses the Z to E isomerase function of the ancestral desaturase CrtI. Biochemical characterization showed that CrtQb is an enzyme with one molecule of tightly bound FAD and acts as a dehydrogenase transferring hydrogen to oxidized plastoquinone.

  19. Purification, Reconstitution, and Inhibition of Cytochrome P-450 Sterol Δ22-Desaturase from the Pathogenic Fungus Candida glabrata

    PubMed Central

    Lamb, David C.; Maspahy, Segula; Kelly, Diane E.; Manning, Nigel J.; Geber, Antonia; Bennett, John E.; Kelly, Steven L.

    1999-01-01

    Sterol Δ22-desaturase has been purified from a strain of Candida glabrata with a disruption in the gene encoding sterol 14α-demethylase (cytochrome P-45051; CYP51). The purified cytochrome P-450 exhibited sterol Δ22-desaturase activity in a reconstituted system with NADPH–cytochrome P-450 reductase in dilaurylphosphatidylcholine, with the enzyme kinetic studies revealing a Km for ergosta-5,7-dienol of 12.5 μM and a Vmax of 0.59 nmol of this substrate metabolized/min/nmol of P-450. This enzyme is encoded by CYP61 (ERG5) in Saccharomyces cerevisiae, and homologues have been shown in the Candida albicans and Schizosaccharomyces pombe genome projects. Ketoconazole, itraconazole, and fluconazole formed low-spin complexes with the ferric cytochrome and exhibited type II spectra, which are indicative of an interaction between the azole moiety and the cytochrome heme. The azole antifungal compounds inhibited reconstituted sterol Δ22-desaturase activity by binding to the cytochrome with a one-to-one stoichiometry, with total inhibition of enzyme activity occurring when equimolar amounts of azole and cytochrome P-450 were added. These results reveal the potential for sterol Δ22-desaturase to be an antifungal target and to contribute to the binding of drugs within the fungal cell. PMID:10390230

  20. 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.

  1. Liver Hemangioma

    MedlinePlus

    Liver hemangioma Overview A liver hemangioma (he-man-jee-O-muh) is a noncancerous (benign) mass in the liver. A liver hemangioma is made up of a tangle of blood vessels. Other terms for a liver hemangioma are hepatic hemangioma and cavernous hemangioma. Most ...

  2. delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

    PubMed

    Cahoon, E B; Cranmer, A M; Shanklin, J; Ohlrogge, J B

    1994-11-04

    delta 6 Hexadecenoic acid (16:1 delta 6) composes more than 80% of the seed oil of Thunbergia alata. Studies were conducted to determine the biosynthetic origin of the double bond of this unusual fatty acid. Assays of fractions of developing T. alata seed endosperm with [1-14C]palmitoyl (16:0)-acyl carrier protein (ACP) revealed the presence of a soluble delta 6 desaturase activity. This activity was greatest when 16:0-ACP was provided as a substrate, whereas no desaturation of the coenzyme A ester of this fatty acid was detected. In addition, delta 6 16:0-ACP desaturase activity in T. alata endosperm extracts was dependent on the presence of ferredoxin and molecular oxygen and was stimulated by catalase. To further characterize this enzyme, a cDNA encoding a diverged acyl-ACP desaturase was isolated from a T. alata endosperm cDNA library using polymerase chain reaction with degenerate oligonucleotides corresponding to conserved amino acid sequences in delta 9 stearoyl (18:0)- and delta 4 16:0-ACP desaturases. The primary structure of the mature peptide encoded by this cDNA shares 66% identity with the mature castor delta 9 18:0-ACP desaturase and 57% identity with the mature coriander delta 4 16:0-ACP desaturase. Extracts of Escherichia coli that express the T. alata cDNA catalyzed the delta 6 desaturation of 16:0-ACP. These results demonstrate that 16:1 delta 6 in T. alata endosperm is formed by the activity of a soluble delta 6 16:0-ACP desaturase that is structurally related to the delta 9 18:0- and delta 4 16:0-ACP desaturases. Implications of this work to an understanding of active site structures of acyl-ACP desaturases are discussed.

  3. Short-Term and Sub-Chronic Dietary Exposure to Aspalathin-Enriched Green Rooibos (Aspalathus linearis) Extract Affects Rat Liver Function and Antioxidant Status.

    PubMed

    van der Merwe, Johanna Debora; de Beer, Dalene; Joubert, Elizabeth; Gelderblom, Wentzel C A

    2015-12-18

    An aspalathin-enriched green rooibos (Aspalathus linearis) extract (GRE) was fed to male Fischer rats in two independent studies for 28 and 90 days. The average dietary total polyphenol (TP) intake was 756 and 627 mg Gallic acid equivalents (GAE)/kg body weight (bw)/day over 28 and 90 days, respectively, equaling human equivalent doses (HEDs) of 123 and 102 GAE mg/kg bw/day. Aspalathin intake of 295 mg/kg bw/day represents a HED of 48 mg/kg bw/day (90 day study). Consumption of GRE increased feed intake significantly (p < 0.05) compared to the control after 90 days, but no effect on body and organ weight parameters was observed. GRE significantly (p < 0.05) reduced serum total cholesterol and iron levels, whilst significantly (p < 0.05) increasing alkaline phosphatase enzyme activity after 90 days. Endogenous antioxidant enzyme activity in the liver, i.e., catalase and superoxide dismutase activity, was not adversely affected. Glutathione reductase activity significantly (p < 0.05) increased after 28 days, while glutathione (GSH) content was decreased after 90 days, suggesting an altered glutathione redox cycle. Quantitative Real Time polymerase chain reaction (PCR) analysis showed altered expression of certain antioxidant defense and oxidative stress related genes, indicative, among others, of an underlying oxidative stress related to changes in the GSH redox pathway and possible biliary dysfunction.

  4. A fish protein hydrolysate alters fatty acid composition in liver and adipose tissue and increases plasma carnitine levels in a mouse model of chronic inflammation.

    PubMed

    Bjørndal, Bodil; Berge, Christ; Ramsvik, Marie Sannes; Svardal, Asbjørn; Bohov, Pavol; Skorve, Jon; Berge, Rolf K

    2013-10-07

    There is growing evidence that fish protein hydrolysate (FPH) diets affect mitochondrial fatty acid metabolism in animals. The aim of the study was to determine if FPH could influence fatty acid metabolism and inflammation in transgene mice expressing human tumor necrosis factor alpha (hTNFα). hTNFα mice (C57BL/6 hTNFα) were given a high-fat (23%, w/w) diet containing 20% casein (control group) or 15% FPH and 5% casein (FPH group) for two weeks. After an overnight fast, blood, adipose tissue, and liver samples were collected. Gene expression and enzyme activity was analysed in liver, fatty acid composition was analyzed in liver and ovarian white adipose tissue, and inflammatory parameters, carnitine, and acylcarnitines were analyzed in plasma. The n-3/n-6 fatty acid ratio was higher in mice fed the FPH diet than in mice fed the control diet in both adipose tissue and liver, and the FPH diet affected the gene expression of ∆6 and ∆9 desaturases. Mice fed this diet also demonstrated lower hepatic activity of fatty acid synthase. Concomitantly, a lower plasma INF-γ level was observed. Plasma carnitine and the carnitine precursor γ-butyrobetaine was higher in the FPH-group compared to control, as was plasma short-chained and medium-chained acylcarnitine esters. The higher level of plasma acetylcarnitine may reflect a stimulated mitochondrial and peroxisomal β-oxidation of fatty acids, as the hepatic activities of peroxisomal acyl-CoA oxidase 1 and mitochondrial carnitine palmitoyltransferase-II were higher in the FPH-fed mice. The FPH diet was shown to influence hepatic fatty acid metabolism and fatty acid composition. This indicates that effects on fatty acid metabolism are important for the bioactivity of protein hydrolysates of marine origin.

  5. Factors affecting operational tolerance after pediatric living-donor liver transplantation: impact of early post-transplant events and HLA match.

    PubMed

    Ohe, Hidenori; Waki, Kayo; Yoshitomi, Mami; Morimoto, Takeshi; Nafady-Hego, Hanaa; Satoda, Naoki; Li, Ying; Zhao, Xiangdong; Sakaguchi, Shimon; Uemoto, Shinji; Bishop, G Alex; Koshiba, Takaaki

    2012-01-01

    Pediatric recipients of living-donor liver transplants (LDLT) can often discontinue immunosuppression (IS). We examined factors affecting development of operational tolerance (OT), defined as off IS for >1 year, in this population. A historic cohort analysis was conducted in 134 pediatric primary semi-allogeneic LDLT. Multivariate logistic regression analysis was used. The frequency of peripheral regulatory T cells (Tregs) was determined at >10 years post-Tx by FACS analysis. IS was successfully discontinued in 84 tolerant patients (Gr-tol), but not in 50 intolerant patients (Gr-intol). The Gr-intol consisted of 24 patients with rejection (Gr-rej) and 26 with fibrosis of grafts (Gr-fib). The absence of early rejection [odds ratio (OR) 2.79, 95% CI 1.11-7.02, P = 0.03], was a positive independent predictor, whereas HLA-A mismatch (0.18, 0.03-0.91, P = 0.04) was a negative predictor. HLA-DR mismatches did not affect OT. The Treg frequency was significantly decreased in Gr-intol (4.9%) compared with Gr-tol (7.6%) (P = 0.003). There were increased levels of tacrolimus in the first week in Gr-Tol (P = 0.02). Although HLA-B mismatch (8.73, 1.09-70.0, P = 0.04) was a positive independent predictor of OT, its clinical significance remains doubtful. In this large cohort of pediatric LDLT recipients, absence of early rejection, HLA-A match and the later predominance of Tregs are factors associated with OT. © 2011 The Authors. Transplant International © 2011 European Society for Organ Transplantation.

  6. Methionine-supplemented diet affects the expression of cardiovascular disease-related genes and increases inflammatory cytokines in mice heart and liver.

    PubMed

    Aissa, Alexandre Ferro; Amaral, Catia Lira do; Venancio, Vinicius Paula; Machado, Carla da Silva; Hernandes, Lívia Cristina; Santos, Patrick Wellington da Silva; Curi, Rui; Bianchi, Maria de Lourdes Pires; Antunes, Lusânia Maria Greggi

    2017-01-01

    Some important environmental factors that influence the development of cardiovascular diseases (CVD) include tobacco, excess alcohol, and unhealthy diet. Methionine obtained from the diet participates in the synthesis of DNA, proteins, lipids and affects homocysteine levels, which is associated with the elevated risk for CVD development. Therefore, the aim of this study was to investigate the manner in which dietary methionine might affect cellular mechanisms underlying CVD occurrence. Swiss albino mice were fed either control (0.3% DL-methionine), methionine-supplemented (2% DL-methionine), or a methionine-deprived diet (0% DL-methionine) over a 10-week period. The parameters measured included plasma homocysteine concentrations, oxidative stress by reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, levels of inflammatory cytokines IL-1ß, TNF-α, and IL-6, as well as expression of genes associated with CVD. The levels of apolipoprotein A5 (APOA5), a regulator of plasma triglycerides, were measured. The methionine-supplemented diet increased oxidative stress by lowering the GSH/GSSG ratio in heart tissues and decreased expression of the genes Apob, Ctgf, Serpinb2, Spp1, Il1b, and Sell, but elevated expression of Thbs4, Tgfb2, Ccr1, and Vegfa. Methionine-deprived diet reduced expression of Col3a1, Cdh5, Fabp3, Bax, and Hbegf and increased expression of Sell, Ccl5, Itga2, Birc3, Msr1, Bcl2a1a, Il1r2, and Selp. Methionine-deprived diet exerted pro-inflammatory consequences as evidenced by elevated levels of cytokines IL-1ß, TNF-α, and IL-6 noted in liver. Methionine-supplemented diet increased hepatic IL-6 and cardiac TNF-α. Both methionine supplementation and deprivation lowered hepatic levels of APOA5. In conclusion, data demonstrated that a methionine-supplemented diet modulated important biological processes associated with high risk of CVD development.

  7. Liver disease

    MedlinePlus

    ... Coccidioidomycosis Delta agent (hepatitis D) Drug-induced cholestasis Fatty liver disease Hemochromatosis Hepatitis A Hepatitis B Hepatitis C ... abscess Reye syndrome Sclerosing cholangitis Wilson disease Images Fatty liver, CT scan Liver with disproportional fattening, CT scan ...

  8. Diabetes mellitus may affect the long-term survival of hepatitis B virus-related hepatocellular carcinoma patients after liver transplantation.

    PubMed

    Zhang, Qing; Deng, Yong-Lin; Liu, Chang; Huang, Li-Hong; Shang, Lei; Chen, Xin-Guo; Wang, Le-Tian; Du, Jin-Zan; Wang, Ying; Wang, Pei-Xiao; Zhang, Hui; Shen, Zhong-Yang

    2016-11-21

    To determine whether diabetes mellitus (DM) affects prognosis/recurrence after liver transplantation (LT) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). A retrospective study was conducted between January 2000 and August 2013 on 1631 patients with HBV-related HCC who underwent LT with antiviral prophylaxis. Patient data were obtained from the China Liver Transplant Registry (https://www.cltr.org/). To compare the outcomes and tumor recurrence in the HBV-related HCC patients with or without DM, statistical analyses were conducted using χ 2 tests, Mann-Whitney tests, the Kaplan-Meier method, log-rank tests and multivariate step-wise Cox regression analysis. Univariate analysis of 1631 patients who underwent LT found overall 1-, 3- and 5-year survival rates of 79%, 73% and 71% respectively in the DM patients, and 84%, 78% and 76% in the non-DM patients respectively. Overall survival rate differences after LT between the two groups were significant ( P = 0.041), but recurrence-free survival rates were not ( P = 0.096). By stratified analysis, the overall survival rates in DM patients for age > 50 years ( P = 0.002), the presence of vascular invasion ( P = 0.096), tumors ≤ 3 cm ( P = 0.047), two to three tumor nodules ( P = 0.007), Child-Pugh grade B ( P = 0.018), and pre-LT alanine aminotransferase levels between 40 and 80 IU/L ( P = 0.017) were significantly lower than in non-DM patients. Additionally, serum α-fetoprotein level > 2000 ng/mL ( P = 0.052) was associated with a significant survival difference trend between DM and non-DM patients. Multivariate analysis showed that the presence of DM ( P < 0.001, HR = 1.591; 95%CI: 1.239-2.041) was an independent predictor associated with poor survival after LT. HBV-related HCC patients with DM have decreased long-term overall survival and poor LT outcomes. Prevention strategies for HCC patients with DM are recommended.

  9. Pregnancy Complications: Liver Disorders

    MedlinePlus

    ... resulting from the liver disorder and decreased bile flow. A pregnant woman should call her health care provider if she has these symptoms. How common is ICP? In the United States, ICP affects less than 1 percent of women ( ...

  10. Inhibitory effects of fenretinide metabolites N-[4-methoxyphenyl]retinamide (MPR) and 4-oxo-N-(4-hydroxyphenyl)retinamide (3-keto-HPR) on fenretinide molecular targets β-carotene oxygenase 1, stearoyl-CoA desaturase 1 and dihydroceramide Δ4-desaturase 1

    PubMed Central

    Poliakov, Eugenia; Samuel, William; Duncan, Todd; Gutierrez, Danielle B.; Mata, Nathan L.; Redmond, T. Michael

    2017-01-01

    The therapeutic capacity of fenretinide (N-[4-hydroxyphenyl] retinamide; 4-HPR) has been demonstrated for several conditions, including cancer, obesity, diabetes, and ocular disease. Yet, the mechanisms of action for its pleiotropic effects are still undefined. We hypothesized that investigation of two of the major physiological metabolites of fenretinide, N-[4-methoxyphenyl]retinamide (MPR) and 4-oxo-N-(4-hydroxyphenyl)retinamide (3-keto-HPR), might begin to resolve the multifaceted effects of this synthetic retinoid. We analyzed the effects of fenretinide, MPR, 3-keto-HPR, and the non-retinoid RBP4 ligand A1120, on the activity of known targets of fenretinide, stearoyl-CoA desaturase 1 (SCD1) and dihydroceramide Δ4-desaturase 1 (DES1) in ARPE-19 cells, and purified recombinant mouse beta-carotene oxygenase 1 (BCO1) in vitro. Lipids and retinoids were extracted and quantified by liquid chromatography-mass spectrometry and reversed phase HPLC, respectively. The data demonstrate that while fenretinide is an inhibitor of the activities of these three enzymes, that 3-keto-HPR is a more potent inhibitor of all three enzymes, potentially mediating most of the in vivo beneficial effects of fenretinide. However, while MPR does not affect SCD1 and DES1 activity, it is a potent specific inhibitor of BCO1. We conclude that a deeper understanding of the mechanisms of action of fenretinide and its metabolites provides new avenues for therapeutic specificity. For example, administration of 3-keto-HPR instead of fenretinide may be preferential if inhibition of SCD1 or DES1 activity is the goal (cancer), while MPR may be better for BCO1 modulation (carotenoid metabolism). Continued investigation of fenretinide metabolites in the context of fenretinide’s various therapeutic uses will begin to resolve the pleotropic nature of this compound. PMID:28448568

  11. Diet-induced non-alcoholic fatty liver disease affects expression of major cytochrome P450 genes in a mouse model.

    PubMed

    Chiba, Tsuyoshi; Noji, Keiko; Shinozaki, Shohei; Suzuki, Sachina; Umegaki, Keizo; Shimokado, Kentaro

    2016-12-01

    Non-alcoholic fatty liver disease (NAFLD) is associated with impaired liver function, and resveratrol could suppress NAFLD progression. This study examined the effects of NAFLD on the expression of major cytochrome P450 (CYP) subtypes in the liver and whether the expression could be attenuated by resveratrol. C57BL/6 mice (male, 10 weeks of age) were fed a high-fat and high-sucrose (HFHS) diet to induce NAFLD. Major Cyp subtype mRNA expression in the liver was measured by real-time RT-PCR. Body and liver weights at 4 and 12 weeks were significantly higher in mice fed the HFHS diet compared with control. The HFHS diet significantly increased the accumulation of cholesterol and triglycerides at 12 weeks. Under this condition, the HFHS diet increased the expression of Cyp1a2 and decreased that of Cyp3a11 at 1 week and thereafter. On the other hand, Cyp1a1, 2b10 and 2c29 mRNA expression levels in the liver were significantly increased at 12 weeks only. Resveratrol (0.05% (w/w) in diet) slightly suppressed lipid accumulation in the liver, but failed to recover impaired Cyp gene expression levels in NAFLD. Drug metabolism may be impaired in NAFLD, and each Cyp subtype is regulated in a different manner. © 2016 Royal Pharmaceutical Society.

  12. Dihydroceramide desaturase inhibition by a cyclopropanated dihydroceramide analog in cultured keratinocytes.

    PubMed

    Brodesser, Susanne; Kolter, Thomas

    2011-01-01

    Most mammalian sphingolipids contain a 4,5-(E)-double bond. We report on the chemical synthesis of a dihydroceramide derivative that prevents the introduction of the double bond into sphingolipids. Minimal alteration of the parent structure by formally replacing the hydrogen atoms in the 5- and in the 6-position of the sphinganine backbone by a methylene group leads to an inhibitor of dihydroceramide desaturase in cultured cells. In the presence of 10-50 μM of compound (1), levels of biosynthetically formed dihydroceramide and-surprisingly-also of phytoceramide are elevated at the expense of ceramide. The cells respond to the lack of unsaturated sphingolipids by an elevation of mRNAs of enzymes required for sphingosine formation. At the same time, the analysis of proliferation and differentiation markers indicates that the sphingolipid double bond is required to keep the cells in a differentiated state.

  13. Dihydroceramide Desaturase Inhibition by a Cyclopropanated Dihydroceramide Analog in Cultured Keratinocytes

    PubMed Central

    Brodesser, Susanne; Kolter, Thomas

    2011-01-01

    Most mammalian sphingolipids contain a 4,5-(E)-double bond. We report on the chemical synthesis of a dihydroceramide derivative that prevents the introduction of the double bond into sphingolipids. Minimal alteration of the parent structure by formally replacing the hydrogen atoms in the 5- and in the 6-position of the sphinganine backbone by a methylene group leads to an inhibitor of dihydroceramide desaturase in cultured cells. In the presence of 10–50 μM of compound (1), levels of biosynthetically formed dihydroceramide and—surprisingly—also of phytoceramide are elevated at the expense of ceramide. The cells respond to the lack of unsaturated sphingolipids by an elevation of mRNAs of enzymes required for sphingosine formation. At the same time, the analysis of proliferation and differentiation markers indicates that the sphingolipid double bond is required to keep the cells in a differentiated state. PMID:21490810

  14. Gut microbiota and liver diseases

    PubMed Central

    Minemura, Masami; Shimizu, Yukihiro

    2015-01-01

    Several studies revealed that gut microbiota are associated with various human diseases, e.g., metabolic diseases, allergies, gastroenterological diseases, and liver diseases. The liver can be greatly affected by changes in gut microbiota due to the entry of gut bacteria or their metabolites into the liver through the portal vein, and the liver-gut axis is important to understand the pathophysiology of several liver diseases, especially non-alcoholic fatty liver disease and hepatic encephalopathy. Moreover, gut microbiota play a significant role in the development of alcoholic liver disease and hepatocarcinogenesis. Based on these previous findings, trials using probiotics have been performed for the prevention or treatment of liver diseases. In this review, we summarize the current understanding of the changes in gut microbiota associated with various liver diseases, and we describe the therapeutic trials of probiotics for those diseases. PMID:25684933

  15. Plasma lipid fatty acid composition, desaturase activities and insulin sensitivity in Amerindian women.

    PubMed

    Vessby, B; Ahrén, B; Warensjö, E; Lindgärde, F

    2012-03-01

    Two Amerindian populations--Shuar women living in the Amazonian rain forest under traditional conditions and urbanized women in a suburb of Lima were studied. The fatty acid composition in plasma lipids and the relationships between fatty acid composition and metabolic variables were studied, as well as in a reference group of Swedish women. Fasting plasma was used for analyses of glucose, insulin, leptin and fatty acid composition. Women in Lima had more body fat, higher fasting insulin and leptin and lower insulin sensitivity than the Shuar women, who had insulin sensitivity similar to Swedish women. Shuar women had very high proportions (mean; SD) of palmitoleic (13.2; 3.9%) and oleic (33.9; 3.7%) acids in the plasma cholesteryl esters with very low levels of linoleic acid (29.1; 6.1 3%), as expected on a low fat, high carbohydrate diet. The estimated activity of delta 9 (SCD-1) desaturase was about twice as high in the Shuar compared with Lima women, suggesting neo lipogenesis, while the delta 5 desaturase activity did not differ. The Lima women, as well as the Swedish, showed strong positive correlations between SCD-1 activity on the one hand and fasting insulin and HOMA index on the other. These associations were absent in the Shuar women. The high SCD-1 activity in the Shuar women may reflect increased lipogenesis in adipose tissue. It also illustrates how a low fat diet rich in non-refined carbohydrates can be linked to a good metabolic situation. Copyright © 2010. Published by Elsevier B.V.

  16. Multiple genes for functional 6 fatty acyl desaturases (Fad) in Atlantic salmon (Salmo salar L.): gene and cDNA characterization, functional expression, tissue distribution and nutritional regulation.

    PubMed

    Monroig, Oscar; Zheng, Xiaozhong; Morais, Sofia; Leaver, Michael J; Taggart, John B; Tocher, Douglas R

    2010-09-01

    Fish are the primary source in the human food basket of the n-3 long-chain polyunsaturated fatty acids, eicosapentaenoate (EPA; 20:5n-3) and docosahexaenoate (DHA; 22:6n-3), that are crucial to the health of higher vertebrates. Atlantic salmon are able to synthesize EPA and DHA from 18:3n-3 through reactions catalyzed by fatty acyl desaturases (Fad) and elongases of very long chain fatty acids. Previously, two cDNAs encoding functionally distinct Delta5 and Delta6 Fads were isolated, but screening of a genomic DNA library revealed the existence of more putative fad genes in the Atlantic salmon genome. In the present study, we show that there are at least four genes encoding putative Fad proteins in Atlantic salmon. Two genes, Delta6fad_a and Delta5fad, corresponded to the previously cloned Delta6 and Delta5 Fad cDNAs. Functional characterization by heterologous expression in yeast showed that the cDNAs for both the two further putative fad genes, Delta6fad_b and Delta6fad_c, had only Delta6 activity, converting 47 % and 12 % of 18:3n-3 to 18:4n-3, and 25 and 7 % of 18:2n-6 to 18:3n-6, for 6Fad_b and Delta6fad_c, respectively. Both 6fad_a and 6fad_b genes were highly expressed in intestine (pyloric caeca), liver and brain, with 6fad_b also highly expressed in gill, whereas 6fad_c transcript was found predominantly in brain, with lower expression levels in all other tissues. The expression levels of the 6fad_a gene in liver and the 6fad_b gene in intestine were significantly higher in fish fed diets containing vegetable oil compared to fish fed fish oil suggesting up-regulation in response to reduced dietary EPA and DHA. In contrast, no significant differences were found between transcript levels for 6fad_a in intestine, 6fad_b in liver, or 6fad_c in liver or intestine of fish fed vegetable oil compared to fish fed fish oil. The observed differences in tissue expression and nutritional regulation of the fad genes are discussed in relation to gene structures and fish

  17. Adipokines in Liver Cirrhosis.

    PubMed

    Buechler, Christa; Haberl, Elisabeth M; Rein-Fischboeck, Lisa; Aslanidis, Charalampos

    2017-06-29

    Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

  18. Adipokines in Liver Cirrhosis

    PubMed Central

    Haberl, Elisabeth M.; Rein-Fischboeck, Lisa; Aslanidis, Charalampos

    2017-01-01

    Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively. PMID:28661458

  19. Catalytic properties of an expressed and purified higher plant type zeta-carotene desaturase from Capsicum annuum.

    PubMed

    Breitenbach, J; Kuntz, M; Takaichi, S; Sandmann, G

    1999-10-01

    The zeta-carotene desaturase from Capsicum annuum (EC 1.14.99.-) was expressed in Escherichia coli, purified and characterized biochemically. The enzyme acts as a monomer with lipophilic quinones as cofactors. Km values for the substrate zeta-carotene or the intermediate neurosporene in the two-step desaturation reaction are almost identical. Product analysis showed that different lycopene isomers are formed, including substantial amounts of the all-trans form, together with 7,7',9,9'-tetracis prolycopene via the corresponding neurosporene isomers. The application of different geometric isomers as substrates revealed that the zeta-carotene desaturase has no preference for certain isomers and that the nature of the isomers formed during catalysis depends strictly on the isomeric composition of the substrate.

  20. WHEAT GERM CELL-FREE TRANSLATION, PURIFICATION, AND ASSEMBLY OF A FUNCTIONAL HUMAN STEAROYL-COA DESATURASE COMPLEX

    PubMed Central

    Goren, Michael A.; Fox, Brian G.

    2008-01-01

    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 b5 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. PMID:18765284

  1. 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.

  2. 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

  3. Stereochemistry of a bifunctional dihydroceramide delta 4-desaturase/hydroxylase from Candida albicans; a key enzyme of sphingolipid metabolism.

    PubMed

    Beckmann, Christoph; Rattke, Janine; Sperling, Petra; Heinz, Ernst; Boland, Wilhelm

    2003-07-21

    The stereochemical course of the dihydroceramide delta 4-(E)-desaturase from Candida albicans, cloned and expressed in the yeast Saccharomyces cerevisiae strain sur2 delta, was determined using stereospecifically labelled (2R,3S)-[2,3,4,4-2H4]-palmitic acid as a metabolic probe. Mass spectrometric analysis of the dinitrophenyl-derivatives of the labelled long-chain bases revealed elimination of a single deuterium atom from C(4) (corresponding to the C(4)-HR) along with a hydrogen atom from C(5) (corresponding to the C(5)-HS). This finding is consistent with an overall syn-elimination of the two vicinal hydrogen atoms. Besides the desaturation product sphingosine (93%) minor amounts of a 4-hydroxylated product (phytosphinganine, 7%) were identified that classify the Candida enzyme as a bifunctional desaturase/hydroxylase. Both processes, desaturation and hydroxylation proceed with loss of C(4)-HR from the chiral precursor. This finding is in agreement with a two-step process involving activation of the substrate by removal of the C(4)-HR to give a C-centred radical or radicaloid followed by either disproportionation into an olefin, water and a reduced diiron complex, or to recombination of the primary reactive intermediate with an active site-bound oxygen to yield a secondary alcohol. This result demonstrates the close mechanistic relationship between desaturation and hydroxylation as two different reaction pathways of a single enzyme and strengthens the mechanistic relationship of desaturases from fatty acid metabolism and sphingolipids.

  4. Dihydrosterculic acid from cottonseed oil suppresses desaturase activity and improves liver metabolomic profiles of high-fat-fed mice

    USDA-ARS?s Scientific Manuscript database

    Consuming a high polyunsaturated fatty acid (PUFA) diet has been shown to cause accumulation of PUFA in skeletal muscle. We have found that increasing the PUFA content in skeletal muscle of mice was associated with increased PPARd expression and activity and we sought to examine the effect of differ...

  5. Cloning and Characterization of Unusual Fatty Acid Desaturases from Anemone leveillei: Identification of an Acyl-Coenzyme A C20 Δ5-Desaturase Responsible for the Synthesis of Sciadonic Acid1

    PubMed Central

    Sayanova, Olga; Haslam, Richard; Venegas Caleron, Monica; Napier, Johnathan A.

    2007-01-01

    The seed oil of Anemone leveillei contains significant amounts of sciadonic acid (20:3Δ5,11,14; SA), an unusual non-methylene-interrupted fatty acid with pharmaceutical potential similar to arachidonic acid. Two candidate cDNAs (AL10 and AL21) for the C20 Δ5cis-desaturase from developing seeds of A. leveillei were functionally characterized in transgenic Arabidopsis (Arabidopsis thaliana) plants. The open reading frames of both Δ5-desaturases showed some similarity to presumptive acyl-coenzyme A (CoA) desaturases found in animals and plants. When expressed in transgenic Arabidopsis, AL21 showed a broad range of substrate specificity, utilizing both saturated (16:0 and 18:0) and unsaturated (18:2, n-6 and 18:3, n-3) substrates. In contrast, AL10 did not show any activity in wild-type Arabidopsis. Coexpression of AL10 or AL21 with a C18 Δ9-elongase in transgenic Arabidopsis plants resulted in the production of SA and juniperonic fatty acid (20:4Δ5,11,14,17). Thus, AL10 acted only on C20 polyunsaturated fatty acids in a manner analogous to “front-end” desaturases. However, neither AL10 nor AL21 contain the cytochrome b5 domain normally present in this class of enzymes. Acyl-CoA profiling of transgenic Arabidopsis plants and developing A. leveillei seeds revealed significant accumulation of Δ5-unsaturated fatty acids as acyl-CoAs compared to the accumulation of these fatty acids in total lipids. Positional analysis of triacylglycerols of A. leveillei seeds showed that Δ5-desaturated fatty acids were present in both sn-2 and sn-1 + sn-3 positions, although the majority of 16:1Δ5, 18:1Δ5, and SA was present at the sn-2 position. Our data provide biochemical evidence for the A. leveillei Δ5-desaturases using acyl-CoA substrates. PMID:17384161

  6. 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

    2017-07-01

    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 D 3 (D 3 ). To separate the experimental effects of sunlight and of all forms of D 3 , a mouse in which UVR does not produce D 3 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 D 3 following UVR exposure of the skin. Thus, unlike in control mice, acute UVR exposure did not affect circulating D 3 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 D 3 following exposure to UVR reflect attenuated production of the D 3 photochemical precursor 7-DHC and, consequently, of D 3 itself. These animals provide a useful new tool for investigating the role of D 3

  7. Liver Immunology

    PubMed Central

    Bogdanos, Dimitrios P.; Gao, Bin; Gershwin, M. Eric

    2014-01-01

    The liver is the largest organ in the body and is generally regarded by non-immunologists as not having lymphoid function. However, such is far from accurate. This review highlights the importance of the liver as a lymphoid organ. Firstly, we discuss experimental data surrounding the role of liver as a lymphoid organ. The liver facilitates a tolerance rather than immunoreactivity, which protects the host from antigenic overload of dietary components and drugs derived from the gut and is also instrumental to fetal immune tolerance. Loss of liver tolerance leads to autoaggressive phenomena which if are not controlled by regulatory lymphoid populations may lead to the induction of autoimmune liver diseases. Liver-related lymphoid subpopulations also act as critical antigen-presenting cells. The study of the immunological properties of liver and delineation of the microenvironment of the intrahepatic milieu in normal and diseased livers provides a platform to understand the hierarchy of a series of detrimental events which lead to immune-mediated destruction of the liver and the rejection of liver allografts. The majority of emphasis within this review will be on the normal mononuclear cell composition of the liver. However, within this context, we will discus select, but not all, immune mediated liver disease and attempt to place these data in the context of human autoimmunity. PMID:23720323

  8. [Functional expression of an omega-3 fatty acid desaturase gene from Glycine max in Saccharomyces cerevisiae].

    PubMed

    Zhang, Hong-Tao; Yang, Jia-Sen; Shan, Lei; Bi, Yu-Ping

    2006-01-01

    Alpha-linolenic acid(ALA, C18:3delta9,12,15 ) is an essential fatty acid which has many sanitary functions to human. However, its contents in diets are often not enough. In plants, omega-3 fatty acid desaturases(FAD) catalyze linoleic acid(LA, C18:2delta9,12) into ALA. The seed oil of Glycine max contains high level of ALA. To investigate the functions of Glycine max omega-3FAD, the cDNA of GmFAD3 C was amplified by RT-PCR from immature seeds, then cloned into the shuttle expression vector p416 to generate the recombinant vector p4GFAD3C. The resulting vector was transformed into Saccharomyces cerevisiae K601 throuth LiAc method. The positive clones were screened on the CM(Ura-) medium and identified by PCR, and then cultured in CM (Ura-) liquid medium with exogenous LA in 20 degrees C for three days. The intracellular fatty acid composition of the engineering strain Kp416 and Kp4GFAD3C was analyzed by gas chromatography (GC). A novel peak in strain Kp4GFAD3C was detected,which was not detectable in control, Comparison of the retention times of the newly yielded peak with that of authentic standard indicated that the fatty acid is ALA. The content of ALA reached to 3.1% of the total fatty acid in recombinant strain, the content of LA correspondingly decreased from 22% to 16.2% by contrast. It was suggested that the protein encoded by GmFAD3 C can specifically catalyze 18 carbon PUFA substrate of LA into ALA by taking off hydrogen atoms at delta15 location. In this study, we expressed a Glycine max omega-3 fatty acid desaturase gene in S. cerevisiae; An efficient and economical yeast expressing system(K601-p416 system) which is suitable for the expression of FAD was built.

  9. Liver Diseases

    MedlinePlus

    Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. There are many kinds of liver diseases: Diseases caused by viruses, such as hepatitis ...

  10. Feeding soy protein isolate and n-3 PUFA affects polycystic liver disease progression in a PCK rat model of autosomal polycystic kidney disease.

    PubMed

    Maditz, Kaitlin H; Benedito, Vagner A; Oldaker, Chris; Nanda, Nainika; Lateef, Sundus S; Livengood, Ryan; Tou, Janet C

    2015-04-01

    In polycystic liver disease (PCLD), multiple cysts cause liver enlargement, structural damage, and loss of function. Soy protein and dietary ω-3 polyunsaturated fatty acids (n-3 PUFAs) have been found to decrease cyst proliferation and inflammation in polycystic kidney disease. Therefore, the aim of the study was to investigate whether soy protein and n-3 PUFA supplementation attenuates PCLD. Young (age 28 days) female PCK rats were fed (n = 12 per group) either casein + corn oil (casein + CO), casein + soybean oil (casein + SO), soy protein isolate + soybean oil (SPI + SO), or SPI + 1:1 soybean/salmon oil blend (SPI + SB) diet for 12 weeks. Liver histology, gene expression by real-time quantitative polymerase chain reaction, and serum markers of liver injury were determined. Diet had no effect on PCLD progression as indicated by no significant differences in liver weight and hepatic proliferation gene expression between diet groups. PCK rats fed SPI + SB diet, however, had the greatest (P < 0.05) histological evidence of hepatic cyst obstruction, portal inflammation, steatosis, and upregulation (P = 0.03) of fibrosis-related genes. Rats fed SPI + SB diet also had the lowest (P < 0.001) serum cholesterol and higher (P < 0.05) serum alkaline phosphatase and bilirubin concentrations. Feeding young female PCK rats SPI and n-3 PUFA failed to attenuate PCLD progression. Furthermore, feeding SPI + SB diet resulted in complications of hepatic steatosis attributable to cysts obstruction of bile duct and hepatic vein. Based on the results, it was concluded that diet intervention alone was not effective at attenuating PCLD associated with autosomal recessive polycystic kidney disease.

  11. Sodium-Glucose Cotransporter 2 Inhibitor and a Low Carbohydrate Diet Affect Gluconeogenesis and Glycogen Content Differently in the Kidney and the Liver of Non-Diabetic Mice.

    PubMed

    Atageldiyeva, Kuralay; Fujita, Yukihiro; Yanagimachi, Tsuyoshi; Mizumoto, Katsutoshi; Takeda, Yasutaka; Honjo, Jun; Takiyama, Yumi; Abiko, Atsuko; Makino, Yuichi; Haneda, Masakazu

    2016-01-01

    A low carbohydrate diet (LCHD) as well as sodium glucose cotransporter 2 inhibitors (SGLT2i) may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCHD) and treated with/without the SGLT-2 inhibitor, ipragliflozin. We compared metabolic parameters, gene expression for transcripts related to glucose and fat metabolism, and glycogen content in the kidney and the liver among the groups. SGLT2i but not LCHD improved glucose excursion after an oral glucose load compared to NCHD, although all groups presented comparable non-fasted glycemia. Both the LCHD and SGLT2i treatments increased calorie-intake, whereas only the LCHD increased body weight compared to the NCHD, epididimal fat mass and developed insulin resistance. Gene expression of certain gluconeogenic enzymes was simultaneously upregulated in the kidney of SGLT2i treated group, as well as in the liver of the LCHD treated group. The SGLT2i treated groups showed markedly lower glycogen content in the liver, but induced glycogen accumulation in the kidney. We conclude that LCHD induces deleterious metabolic changes in the non-diabetic mice. Our results suggest that SGLT2i induced gluconeogenesis mainly in the kidney, whereas for LCHD it was predominantly in the liver.

  12. Sodium-Glucose Cotransporter 2 Inhibitor and a Low Carbohydrate Diet Affect Gluconeogenesis and Glycogen Content Differently in the Kidney and the Liver of Non-Diabetic Mice

    PubMed Central

    Atageldiyeva, Kuralay; Fujita, Yukihiro; Yanagimachi, Tsuyoshi; Mizumoto, Katsutoshi; Takeda, Yasutaka; Honjo, Jun; Takiyama, Yumi; Abiko, Atsuko; Makino, Yuichi; Haneda, Masakazu

    2016-01-01

    A low carbohydrate diet (LCHD) as well as sodium glucose cotransporter 2 inhibitors (SGLT2i) may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCHD) and treated with/without the SGLT-2 inhibitor, ipragliflozin. We compared metabolic parameters, gene expression for transcripts related to glucose and fat metabolism, and glycogen content in the kidney and the liver among the groups. SGLT2i but not LCHD improved glucose excursion after an oral glucose load compared to NCHD, although all groups presented comparable non-fasted glycemia. Both the LCHD and SGLT2i treatments increased calorie-intake, whereas only the LCHD increased body weight compared to the NCHD, epididimal fat mass and developed insulin resistance. Gene expression of certain gluconeogenic enzymes was simultaneously upregulated in the kidney of SGLT2i treated group, as well as in the liver of the LCHD treated group. The SGLT2i treated groups showed markedly lower glycogen content in the liver, but induced glycogen accumulation in the kidney. We conclude that LCHD induces deleterious metabolic changes in the non-diabetic mice. Our results suggest that SGLT2i induced gluconeogenesis mainly in the kidney, whereas for LCHD it was predominantly in the liver. PMID:27327650

  13. Sacubitril Is Selectively Activated by Carboxylesterase 1 (CES1) in the Liver and the Activation Is Affected by CES1 Genetic Variation.

    PubMed

    Shi, Jian; Wang, Xinwen; Nguyen, Jenny; Wu, Audrey H; Bleske, Barry E; Zhu, Hao-Jie

    2016-04-01

    Sacubitril was recently approved by the Food and Drug Administration for use in combination with valsartan for the treatment of patients with heart failure with reduced ejection fraction. As a prodrug, sacubitril must be metabolized (hydrolyzed) to its active metabolite sacubitrilat (LBQ657) to exert its intended therapeutic effects. Thus, understanding the determinants of sacubitril activation will lead to the improvement of sacubitril pharmacotherapy. The objective of this study was to identify the enzyme(s) responsible for the activation of sacubitril, and determine the impact of genetic variation on sacubitril activation. First, an incubation study of sacubitril with human plasma and the S9 fractions of human liver, intestine, and kidney was conducted. Sacubitril was found to be activated by human liver S9 fractions only. Moreover, sacubitril activation was significantly inhibited by the carboxylesterase 1 (CES1) inhibitor bis-(p-nitrophenyl) phosphate in human liver S9. Further incubation studies with recombinant human CES1 and carboxylesterase 2 confirmed that sacubitril is a selective CES1 substrate. The in vitro study of cell lines transfected with wild-type CES1 and the CES1 variant G143E (rs71647871) demonstrated that G143E is a loss-of-function variant for sacubitril activation. Importantly, sacubitril activation was significantly impaired in human livers carrying the G143E variant. In conclusion, sacubitril is selectively activated by CES1 in human liver. The CES1 genetic variant G143E can significantly impair sacubitril activation. Therefore, CES1 genetic variants appear to be an important contributing factor to interindividual variability in sacubitril activation, and have the potential to serve as biomarkers to optimize sacubitril pharmacotherapy. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Sacubitril Is Selectively Activated by Carboxylesterase 1 (CES1) in the Liver and the Activation Is Affected by CES1 Genetic Variation

    PubMed Central

    Shi, Jian; Wang, Xinwen; Nguyen, Jenny; Wu, Audrey H.; Bleske, Barry E.

    2016-01-01

    Sacubitril was recently approved by the Food and Drug Administration for use in combination with valsartan for the treatment of patients with heart failure with reduced ejection fraction. As a prodrug, sacubitril must be metabolized (hydrolyzed) to its active metabolite sacubitrilat (LBQ657) to exert its intended therapeutic effects. Thus, understanding the determinants of sacubitril activation will lead to the improvement of sacubitril pharmacotherapy. The objective of this study was to identify the enzyme(s) responsible for the activation of sacubitril, and determine the impact of genetic variation on sacubitril activation. First, an incubation study of sacubitril with human plasma and the S9 fractions of human liver, intestine, and kidney was conducted. Sacubitril was found to be activated by human liver S9 fractions only. Moreover, sacubitril activation was significantly inhibited by the carboxylesterase 1 (CES1) inhibitor bis-(p-nitrophenyl) phosphate in human liver S9. Further incubation studies with recombinant human CES1 and carboxylesterase 2 confirmed that sacubitril is a selective CES1 substrate. The in vitro study of cell lines transfected with wild-type CES1 and the CES1 variant G143E (rs71647871) demonstrated that G143E is a loss-of-function variant for sacubitril activation. Importantly, sacubitril activation was significantly impaired in human livers carrying the G143E variant. In conclusion, sacubitril is selectively activated by CES1 in human liver. The CES1 genetic variant G143E can significantly impair sacubitril activation. Therefore, CES1 genetic variants appear to be an important contributing factor to interindividual variability in sacubitril activation, and have the potential to serve as biomarkers to optimize sacubitril pharmacotherapy. PMID:26817948

  15. Feeding steam-pelleted rapeseed affects expression of genes involved in hepatic lipid metabolism and fatty acid composition of chicken meat.

    PubMed

    Li, S; Vestergren, A Schiller; Wall, H; Trattner, S; Pickova, J; Ivarsson, E

    2017-08-01

    This study investigated the dietary effect of steam-pelleted rapeseed (RS) diets with different inclusion levels on the fatty acid composition of chicken meat and the expression of lipid metabolism-related genes in the liver. Experimental diets included 6 different wheat-soybean meal based diets either in nonpelleted or steam-pelleted form supplemented with 80, 160, and 240 g RS/kg feed and one nonpelleted wheat-soybean meal based diet without RS supplementation as the control. These diets were fed to newly hatched broiler chickens (Ross 308) for 34 days. Compared to the control diet, steam-pelleted diets containing 160 or 240 g/kg RS significantly increased the content of omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) in the breast and drumstick, while their meat yields were not affected. Moreover, the mRNA levels of fatty acid desaturase 1 (FADS1) and acyl-coenzyme A oxidase 1 (ACOX1) in their livers increased. Therefore, steam-pelleted diets with 160 or 240 g/kg RS can be used to increase the n-3 LC-PUFA content in chicken meat without compromising meat yield. © 2017 Poultry Science Association Inc.

  16. Ablation of Dihydroceramide Desaturase Confers Resistance to Etoposide-Induced Apoptosis In Vitro

    PubMed Central

    Siddique, Monowarul M.; Bikman, Benjamin T.; Wang, Liping; Ying, Li; Reinhardt, Erin; Shui, Guanghou; Wenk, Markus R.; Summers, Scott A.

    2012-01-01

    Sphingolipid biosynthesis is potently upregulated by factors associated with cellular stress, including numerous chemotherapeutics, inflammatory cytokines, and glucocorticoids. Dihydroceramide desaturase 1 (Des1), the third enzyme in the highly conserved pathway driving sphingolipid biosynthesis, introduces the 4,5-trans-double bond that typifies most higher-order sphingolipids. Surprisingly, recent studies have shown that certain chemotherapeutics and other drugs inhibit Des1, giving rise to a number of sphingolipids that lack the characteristic double bond. In order to assess the effect of an altered sphingolipid profile (via Des1 inhibition) on cell function, we generated isogenic mouse embryonic fibroblasts lacking both Des1 alleles. Lipidomic profiling revealed that these cells contained higher levels of dihydroceramide than wild-type fibroblasts and that complex sphingolipids were comprised predominantly of the saturated backbone (e.g. sphinganine vs. sphingosine, dihydrosphingomyelin vs. sphingomyelin, etc.). Des1 ablation activated pro-survival and anabolic signaling intermediates (e.g. Akt/PKB, mTOR, MAPK, etc.) and provided protection from apoptosis caused by etoposide, a chemotherapeutic that induces sphingolipid synthesis by upregulating several sphingolipid biosynthesizing enzymes. These data reveal that the double bond present in most sphingolipids has a profound impact on cell survival pathways, and that the manipulation of Des1 could have important effects on apoptosis. PMID:22984457

  17. Dehydrosqualene Desaturase as a Novel Target for Anti-Virulence Therapy against Staphylococcus aureus.

    PubMed

    Gao, Peng; Davies, Julian; Kao, Richard Yi Tsun

    2017-09-05

    Staphylococcus aureus , especially methicillin-resistant S. aureus (MRSA), is a life-threatening pathogen in hospital- and community-acquired infections. The golden-colored carotenoid pigment of S. aureus , staphyloxanthin, contributes to the resistance to reactive oxygen species (ROS) and host neutrophil-based killing. Here, we describe a novel inhibitor (NP16) of S. aureus pigment production that reduces the survival of S. aureus under oxidative stress conditions. Carotenoid components analysis, enzyme inhibition, and crtN mutational studies indicated that the molecular target of NP16 is dehydrosqualene desaturase (CrtN). S. aureus treated with NP16 showed increased susceptibility to human neutrophil killing and to innate immune clearance in a mouse infection model. Our study validates CrtN as a novel druggable target in S. aureus and presents a potent and effective lead compound for the development of virulence factor-based therapy against S. aureus IMPORTANCE S. aureus staphyloxanthin contributes substantially to pathogenesis by interfering with host immune clearance mechanisms, but it has little impact on ex vivo survival of the bacterium. Agents blocking staphyloxanthin production may discourage the establishment and maintenance of bacterial infection without exerting selective pressure for antimicrobial resistance. Our newly discovered CrtN inhibitor, NP16, may offer an effective strategy for combating S. aureus infections. Copyright © 2017 Gao et al.

  18. Elevated Stearoyl-CoA Desaturase in Brains of Patients with Alzheimer's Disease

    PubMed Central

    Astarita, Giuseppe; Jung, Kwang-Mook; Vasilevko, Vitaly; DiPatrizio, Nicholas V.; Martin, Sarah K.; Cribbs, David H.; Head, Elizabeth; Cotman, Carl W.; Piomelli, Daniele

    2011-01-01

    The molecular bases of Alzheimer's disease (AD) remain unclear. We used a lipidomic approach to identify lipid abnormalities in the brains of subjects with AD (N = 37) compared to age-matched controls (N = 17). The analyses revealed statistically detectable elevations in levels of non-esterified monounsaturated fatty acids (MUFAs) and mead acid (20:3n-9) in mid-frontal cortex, temporal cortex and hippocampus of AD patients. Further studies showed that brain mRNAs encoding for isoforms of the rate-limiting enzyme in MUFAs biosynthesis, stearoyl-CoA desaturase (SCD-1, SCD-5a and SCD-5b), were elevated in subjects with AD. The monounsaturated/saturated fatty acid ratio (‘desaturation index’) – displayed a strong negative correlation with measures of cognition: the Mini Mental State Examination test (r = −0.80; P = 0.0001) and the Boston Naming test (r = −0.57; P = 0.0071). Our results reveal a previously unrecognized role for the lipogenic enzyme SCD in AD. PMID:22046234

  19. Associations between a fatty acid desaturase gene polymorphism and blood arachidonic acid compositions in Japanese elderly.

    PubMed

    Horiguchi, Sayaka; Nakayama, Kazuhiro; Iwamoto, Sadahiko; Ishijima, Akiko; Minezaki, Takayuki; Baba, Mamiko; Kontai, Yoshiko; Horikawa, Chika; Kawashima, Hiroshi; Shibata, Hiroshi; Kagawa, Yasuo; Kawabata, Terue

    2016-02-01

    We investigated whether the single nucleotide polymorphism rs174547 (T/C) of the fatty acid desaturase-1 gene, FADS1, is associated with changes in erythrocyte membrane and plasma phospholipid (PL) long-chain polyunsaturated fatty acid (LCPUFA) composition in elderly Japanese participants (n=124; 65 years or older; self-feeding and oral intake). The rs174547 C-allele carriers had significantly lower arachidonic acid (ARA; n-6 PUFA) and higher linoleic acid (LA, n-6 PUFA precursor) levels in erythrocyte membrane and plasma PL (15% and 6% ARA reduction, respectively, per C-allele), suggesting a low LA to ARA conversion rate in erythrocyte membrane and plasma PL of C-allele carriers. α-linolenic acid (n-3 PUFA precursor) levels were higher in the plasma PL of C-allele carriers, whereas levels of the n-3 LCPUFAs eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) were unchanged in erythrocyte membrane and plasma PL. Thus, rs174547 genotypes were significantly associated with different ARA compositions of the blood of elderly Japanese. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2016-03-01

    Endogenous synthesis of the long-chain polyunsaturated fatty acids (LCPUFAs) 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). Although 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. Genome-wide association study (GWAS) of Greenland Inuit shows 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. An SNP near FADS1 influences the levels of 5-lipoxygenase products and epigenetic alteration. Genetic polymorphisms within FADS and ELOVL can limit LCPUFA product accumulation at any step of the biosynthetic pathway.

  1. A Novel Sterol Desaturase-Like Protein Promoting Dealkylation of Phytosterols in Tetrahymena thermophila▿

    PubMed Central

    Tomazic, Mariela L.; Najle, Sebastián R.; Nusblat, Alejandro D.; Uttaro, Antonio D.; Nudel, Clara B.

    2011-01-01

    The gene TTHERM_00438800 (DES24) from the ciliate Tetrahymena thermophila encodes a protein with three conserved histidine clusters, typical of the fatty acid hydroxylase superfamily. Despite its high similarity to sterol desaturase-like enzymes, the phylogenetic analysis groups Des24p in a separate cluster more related to bacterial than to eukaryotic proteins, suggesting a possible horizontal gene transfer event. A somatic knockout of DES24 revealed that the gene encodes a protein, Des24p, which is involved in the dealkylation of phytosterols. Knocked-out mutants were unable to eliminate the C-24 ethyl group from C29 sterols, whereas the ability to introduce other modifications, such as desaturations at positions C-5(6), C-7(8), and C-22(23), were not altered. Although C-24 dealkylations have been described in other organisms, such as insects, neither the enzymes nor the corresponding genes have been identified to date. Therefore, this is the first identification of a gene involved in sterol dealkylation. Moreover, the knockout mutant and wild-type strain differed significantly in growth and morphology only when cultivated with C29 sterols; under this culture condition, a change from the typical pear-like shape to a round shape and an alteration in the regulation of tetrahymanol biosynthesis were observed. Sterol analysis upon culture with various substrates and inhibitors indicate that the removal of the C-24 ethyl group in Tetrahymena may proceed by a mechanism different from the one currently known. PMID:21257793

  2. Improved soybean oil quality by targeted mutagenesis of the fatty acid desaturase 2 gene family.

    PubMed

    Haun, William; Coffman, Andrew; Clasen, Benjamin M; Demorest, Zachary L; Lowy, Anita; Ray, Erin; Retterath, Adam; Stoddard, Thomas; Juillerat, Alexandre; Cedrone, Frederic; Mathis, Luc; Voytas, Daniel F; Zhang, Feng

    2014-09-01

    Soybean oil is high in polyunsaturated fats and is often partially hydrogenated to increase its shelf life and improve oxidative stability. The trans-fatty acids produced through hydrogenation pose a health threat. Soybean lines that are low in polyunsaturated fats were generated by introducing mutations in two fatty acid desaturase 2 genes (FAD2-1A and FAD2-1B), which in the seed convert the monounsaturated fat, oleic acid, to the polyunsaturated fat, linoleic acid. Transcription activator-like effector nucleases (TALENs) were engineered to recognize and cleave conserved DNA sequences in both genes. In four of 19 transgenic soybean lines expressing the TALENs, mutations in FAD2-1A and FAD2-1B were observed in DNA extracted from leaf tissue; three of the four lines transmitted heritable FAD2-1 mutations to the next generation. The fatty acid profile of the seed was dramatically changed in plants homozygous for mutations in both FAD2-1A and FAD2-1B: oleic acid increased from 20% to 80% and linoleic acid decreased from 50% to under 4%. Further, mutant plants were identified that lacked the TALEN transgene and only carried the targeted mutations. The ability to create a valuable trait in a single generation through targeted modification of a gene family demonstrates the power of TALENs for genome engineering and crop improvement. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Alcoholic liver disease: The gut microbiome and liver crosstalk

    PubMed Central

    Hartmann, Phillipp; Seebauer, Caroline T.; Schnabl, Bernd

    2015-01-01

    Alcoholic liver disease is a leading cause of morbidity and mortality worldwide. Alcoholic fatty liver disease can progress to steatohepatitis, alcoholic hepatitis, fibrosis, and cirrhosis. Patients with alcohol abuse show quantitative and qualitative changes in the composition of the intestinal microbiome. Furthermore, patients with alcoholic liver disease have increased intestinal permeability and elevated systemic levels of gut-derived microbial products. Maintaining eubiosis, stabilizing the mucosal gut barrier or preventing cellular responses to microbial products protect from experimental alcoholic liver disease. Therefore, intestinal dysbiosis and pathological bacterial translocation appear fundamental for the pathogenesis of alcoholic liver disease. This review highlights causes for intestinal dysbiosis and pathological bacterial translocation, their relationship and consequences for alcoholic liver disease. We also discuss how the liver affects the intestinal microbiota. PMID:25872593

  4. A New F131V Mutation in Chlamydomonas Phytoene Desaturase Locates a Cluster of Norflurazon Resistance Mutations near the FAD-Binding Site in 3D Protein Models

    PubMed Central

    Suarez, Julio V.; Banks, Stephen; Thomas, Paul G.; Day, Anil

    2014-01-01

    The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. We isolated a UV-induced mutant able to grow in very high concentrations of norflurazon (150 µM). The phytoene desaturase gene in the mutant strain contained the first resistance mutation to be localised to the dinucleotide-binding Rossmann-likedomain. A highly conserved phenylalanine amino acid at position 131 of the 564 amino acid precursor protein was changed to a valine in the mutant protein. F131, and two other amino acids whose substitution confers norflurazon resistance in homologous phytoene desaturase proteins, map to distant regions in the primary sequence of the C. reinhardtii protein (V472, L505) but in tertiary models these residues cluster together to a region close to the predicted FAD binding site. The mutant gene allowed direct 5 µM norflurazon based selection of transformants, which were tolerant to other bleaching herbicides including fluridone, flurtamone, and diflufenican but were more sensitive to beflubutamid than wild type cells. Norflurazon resistance and beflubutamid sensitivity allow either positive or negative selection against transformants expressing the mutant phytoene desaturase gene. PMID:24936791

  5. Sunitinib-ibuprofen drug interaction affects the pharmacokinetics and tissue distribution of sunitinib to brain, liver, and kidney in male and female mice differently.

    PubMed

    Lau, Christine Li Ling; Chan, Sook Tyng; Selvaratanam, Manimegahlai; Khoo, Hui Wen; Lim, Adeline Yi Ling; Modamio, Pilar; Mariño, Eduardo L; Segarra, Ignacio

    2015-08-01

    Tyrosine kinase inhibitor sunitinib (used in GIST, advanced RCC, and pancreatic neuroendocrine tumors) undergoes CYP3A4 metabolism and is an ABCB1B and ABCG2 efflux transporters substrate. We assessed the pharmacokinetic interaction with ibuprofen (an NSAID used by patients with cancer) in Balb/c male and female mice. Mice (study group) were coadministered (30 min apart) 30 mg/kg of ibuprofen and 60 mg/kg of sunitinib PO and compared with the control groups, which received sunitinib alone (60 mg/kg, PO). Sunitinib concentration in plasma, brain, kidney, and liver was measured by HPLC as scheduled and noncompartmental pharmacokinetic parameters estimated. In female control mice, sunitinib AUC0→∞ decreased in plasma (P < 0.05), was higher in liver and brain (P < 0.001), and lower in kidney (P < 0.001) vs. male control mice. After ibuprofen coadministration, female mice showed lower AUC0→∞ in plasma (P < 0.01), brain, liver, and kidney (all P < 0.001). However, in male mice, AUC0→∞ remained unchanged in plasma, increased in liver and kidney, and decreased in brain (all P < 0.001). The tissue-to-plasma AUC0→∞ ratio was similar between male and female control mice, but changed after ibuprofen coadministration: Male mice showed 1.6-fold higher liver-to-plasma ratio (P < 0.001) while remained unchanged in female mice and in kidney (male and female mice) but decreased 55% in brain (P < 0.05). The tissue-to-plasma partial AUC ratio, the drug tissue targeting index, and the tissue-plasma hysteresis-like plots also showed sex-based ibuprofen-sunitinib drug interaction differences. The results illustrate the relevance of this DDI on sunitinib pharmacokinetics and tissue uptake. These may be due to gender-based P450 and efflux/transporters differences. © 2015 Société Française de Pharmacologie et de Thérapeutique.

  6. 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.

  7. Low salinity affects cellularity, DNA methylation, and mRNA expression of igf1 in the liver of half smooth tongue sole (Cynoglossus semilaevis).

    PubMed

    Li, Siping; He, Feng; Wen, Haishen; Li, Jifang; Si, Yufeng; Liu, Mingyuan; Huang, Yajuan; Meng, Lingcai

    2017-12-01

    Animal growth depends on feedback regulation of hormone levels and environmental conditions. Insulin-like growth factor-1 (Igf1) promotes cell growth and differentiation and represses apoptosis and is highly regulated by the environment. Moreover, animals modify physiological homeostasis under stressful conditions through epigenetics and genetic regulatory mechanisms. Therefore, a comprehensive understanding of the effects of salt on fish growth is needed. In this study, half smooth tongue sole (Cynoglossus semilaevis) were subjected to 15‰ salinity for 0, 7, and 60 days (D) to assess the effects of low salinity on liver cellularity and growth. The results show that low salinity changed liver morphology, suggesting an increase in energy expenditure to recover from the osmotic disruption. igf1 was upregulated in female fish under 15‰ salinity after 7D and may participate in molecular repair. igf1 was downregulated after 60D of salt stress, resulting in retarded growth. Methylation levels were opposite to those of gene expression, suggesting inhibited regulation. Furthermore, three exons in the igf1 gene had significantly different methylation levels in fish under salt stress. Notably, more putative transcription factor binding sites were located in CpG sites at higher methylation levels. igf1 is not a sex-related gene, as no difference in methylation level was detected between males and females in the control group. These results clarify liver damage and changes in DNA methylation and mRNA expression of igf1, providing insight into the adverse effects of low salt on growth of C. semilaevis and the epigenetics and regulatory mechanisms involved in stressful conditions.

  8. Chronic administration of saturated fats and fructose differently affect SREBP activity resulting in different modulation of Nrf2 and Nlrp3 inflammasome pathways in mice liver.

    PubMed

    Nigro, Debora; Menotti, Francesca; Cento, Alessia S; Serpe, Loredana; Chiazza, Fausto; Dal Bello, Federica; Romaniello, Francesco; Medana, Claudio; Collino, Massimo; Aragno, Manuela; Mastrocola, Raffaella

    2017-04-01

    The overconsumption of both saturated fats and fructose in the modern society has been related to the development of nonalcoholic fatty liver disease (NAFLD). However, the specific contribution of individual dietary components on the progression of NAFLD to nonalcoholic steatohepatitis (NASH) has been poorly investigated. Therefore, the aim of our study was to investigate the dissimilar effects of these two dietary components on selected proinflammatory and antioxidant pathways in the liver of C57BL/6 mice fed a standard (SD), a 45% saturated fat (HFAT) or a 60% fructose (HFRT) diet for 12 weeks. HFAT diet evoked systemic metabolic alterations and overweight, not observed in HFRT mice. However, HFRT mice had a greater hepatic triglyceride deposition with increased ratio of triacylglycerols containing the palmitic acid compared to HFAT, as assessed by liquid chromatography-mass spectrometry analysis. This effect is due to the higher activation of the SCAP/SREBP1c lipogenic pathway by HFRT feeding. In addition, we found inhibition of Keap1/Nrf2 antioxidant signaling and more robust stimulation of the Nlrp3 inflammasome pathway in the livers of HFRT-fed mice when compared with HFAT-fed mice, which is consistent with the recent finding that palmitate and SREBP1c are implicated in hepatic oxidative stress and inflammation. These effects were associated with increased hepatic inflammation, as confirmed by high expression of markers of leukocyte infiltration in the HFRT group. Thus, we hypothesize an amplifying loop among lipogenesis, palmitate, Nrf2 and Nlrp3 that leads to a higher risk of NAFLD progression to NASH in a high-fructose diet compared to a high-saturated fat intake. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Liver anatomy.

    PubMed

    Abdel-Misih, Sherif R Z; Bloomston, Mark

    2010-08-01

    Understanding the complexities of the liver has been a long-standing challenge to physicians and anatomists. Significant strides in the understanding of hepatic anatomy have facilitated major progress in liver-directed therapies--surgical interventions, such as transplantation, hepatic resection, hepatic artery infusion pumps, and hepatic ablation, and interventional radiologic procedures, such as transarterial chemoembolization, selective internal radiation therapy, and portal vein embolization. Without understanding hepatic anatomy, such progressive interventions would not be feasible. This article reviews the history, general anatomy, and the classification schemes of liver anatomy and their relevance to liver-directed therapies. Copyright 2010 Elsevier Inc. All rights reserved.

  10. 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 (C 26:1 , C 28:1 , and C 30:1 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. © 2017 American Society of Plant Biologists. All Rights Reserved.

  11. Absence of stearoyl-CoA desaturase-1 does not promote DSS-induced acute colitis.

    PubMed

    Macdonald, Marcia L E; Bissada, Nagat; Vallance, Bruce A; Hayden, Michael R

    2009-12-01

    Absence of stearoyl-CoA desaturase-1 (SCD1) in mice leads to chronic inflammation of the skin and increased susceptibility to atherosclerosis, while also increasing plasma inflammatory markers. A recent report suggested that SCD1 deficiency also increases disease severity in a mouse model of inflammatory bowel disease, induced by dextran sulfate sodium (DSS). However, SCD1-deficient mice are known to consume increased amounts of water, which would also be expected to increase the intake of DSS-treated water. The aim of this study was to determine the effect of SCD1 deficiency on DSS-induced acute colitis with DSS dosing adjusted to account for genotype differences in fluid consumption. Wild-type controls were treated with 3.5% DSS for 5 days to induce moderately severe colitis, while the concentration of DSS given to SCD1-deficient mice was lowered to 2.5% to control for increased fluid consumption. Colonic inflammation was assessed by clinical and histological scoring. Although SCD1-deficient mice consumed a total intake of DSS that was greater than that of wild-type controls, colonic inflammation, colon length and fecal blood were not altered by SCD1-deficiency in DSS-induced colitis, while diarrhea and total weight loss were modestly improved. Despite SCD1 deficiency leading to chronic inflammation of the skin and increased susceptibility to atherosclerosis, it does not accelerate inflammation in the DSS-induced model of acute colitis when DSS intake is controlled. These observations suggest that SCD1 deficiency does not play a significant role in colonic inflammation in this model.

  12. 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.

  13. Plasma fatty acid composition, estimated desaturase activities, and their relation with the metabolic syndrome in a population at high risk of cardiovascular disease.

    PubMed

    Mayneris-Perxachs, Jordi; Guerendiain, Marcela; Castellote, Ana I; Estruch, Ramón; Covas, María Isabel; Fitó, Montserrat; Salas-Salvadó, Jordi; Martínez-González, Miguel A; Aros, Fernando; Lamuela-Raventós, Rosa M; López-Sabater, M Carmen

    2014-02-01

    The metabolic syndrome (MetS) is a clustering of various metabolic abnormalities which is associated with increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus. Due to its increasing prevalence, it has become an important public health concern. Altered fatty acid (FA) composition and desaturase activities have been associated with several metabolic diseases, including MetS. The aim of the present study was to evaluate the relationship of the plasma FA profile and desaturase activities with the MetS in a Mediterranean population at high risk of CVD. Baseline data from 427 participants aged 55-80 years who took part in the interventional PREDIMED study were obtained. Individual FA was determined in plasma and desaturase activities were estimated from product/precursor ratios. Odds ratios (OR) and partial correlation coefficients were used to examine these relations with MetS and its components, respectively. We found higher levels of C14:0, C16:0, C16:1n-7, estimated Δ(9)- or stearoyl-CoA desaturase (SCD), and estimated Δ(6) desaturase (D6D), and lower levels of C18:2n-6 in people with MetS compared to those without it. After adjustment for several confounders, only higher quartiles of C14:0, C16:0, C16:1n-7, and D6D were found to be associated with an increasing prevalence of MetS, while higher quartiles of C18:2n-6 were inversely associated with MetS. High proportions of C14:0, C16:0, C16:1n-7, C20:3n-6, SCD, and D6D, and decreased proportions of C18:2n-6 and estimated Δ(5)-desaturase (D5D) were associated with adverse profiles of several metabolic risk factors. Women showed more unhealthy FA pattern and lipid profiles than men, but only among those with MetS. A FA composition and estimated desaturase activities consisting in high levels of SFA, SCD and D6D, and low levels of PUFA and D5D are associated with increased MetS probability and are characteristic of people presenting MetS, especially women. These findings support those observed

  14. Homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8

    PubMed Central

    Garba, Lawal; Mohamad Yussoff, Mohamad Ariff; Abd Halim, Khairul Bariyyah; Ishak, Siti Nor Hasmah; Mohamad Ali, Mohd Shukuri; Oslan, Siti Nurbaya

    2018-01-01

    Membrane-bound fatty acid desaturases perform oxygenated desaturation reactions to insert double bonds within fatty acyl chains in regioselective and stereoselective manners. The Δ9-fatty acid desaturase strictly creates the first double bond between C9 and 10 positions of most saturated substrates. As the three-dimensional structures of the bacterial membrane fatty acid desaturases are not available, relevant information about the enzymes are derived from their amino acid sequences, site-directed mutagenesis and domain swapping in similar membrane-bound desaturases. The cold-tolerant Pseudomonas sp. AMS8 was found to produce high amount of monounsaturated fatty acids at low temperature. Subsequently, an active Δ9-fatty acid desaturase was isolated and functionally expressed in Escherichia coli. In this paper we report homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8 for the first time to the best of our knowledge. Three dimensional structure of the enzyme was built using MODELLER version 9.18 using a suitable template. The protein model contained the three conserved-histidine residues typical for all membrane-bound desaturase catalytic activity. The structure was subjected to energy minimization and checked for correctness using Ramachandran plots and ERRAT, which showed a good quality model of 91.6 and 65.0%, respectively. The protein model was used to preform MD simulation and docking of palmitic acid using CHARMM36 force field in GROMACS Version 5 and Autodock tool Version 4.2, respectively. The docking simulation with the lowest binding energy, −6.8 kcal/mol had a number of residues in close contact with the docked palmitic acid namely, Ile26, Tyr95, Val179, Gly180, Pro64, Glu203, His34, His206, His71, Arg182, Thr85, Lys98 and His177. Interestingly, among the binding residues are His34, His71 and His206 from the first, second, and third conserved histidine motif, respectively, which constitute

  15. Factors Affecting Detection of Hepatitis E Virus on Canadian Retail Pork Chops and Pork Livers Assayed Using Real-Time RT-PCR.

    PubMed

    Wilhelm, B J; Leblanc, D; Avery, B; Pearl, D L; Houde, A; Rajić, A; McEwen, S A

    2016-03-01

    We collected 599 Canadian retail pork chops and 283 pork livers routinely (usually weekly) from April 2011 to March 2012 using the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) retail sampling platform. Samples were assayed using validated real-time (q) reverse transcriptase polymerase chain reaction (RT-PCR) and nested classical RT-PCR for the detection of hepatitis E virus (HEV), porcine enteric calicivirus (PEC) and rotavirus (RV). The presence of Escherichia coli, Salmonella spp. and Campylobacter spp. was measured on a subset of our samples. Exact logistic regression models were fitted for predictors for HEV detection, for each assay. For both assays, sample type (pork chop versus liver) was a significant predictor for HEV RNA detection. For nested classical RT-PCR but not qRT-PCR, region of sample collection was a significant predictor (P = 0.008) of HEV detection. Odds of HEV detection were greatest in spring relative to other seasons. E. coli was a significant predictor for HEV RNA detection using the qRT-PCR (P = 0.03). Overall, the prevalence of E. coli, Salmonella spp. and Campylobacter spp. was significantly greater than HEV, PEC or RV on our retail pork samples. Our sparse data set for the detection of PEC and RV precluded modelling of risk factors for the detection of these viruses. © 2015 Zoonoses and Public Health © 2015 Her Majesty the Queen in Right of Canada Reproduced with the permission of the Minister of the Public Health Agency of Canada.

  16. Liver spots

    MedlinePlus

    Sun-induced skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun or other sources of ...

  17. Experimental models of liver fibrosis.

    PubMed

    Yanguas, Sara Crespo; Cogliati, Bruno; Willebrords, Joost; Maes, Michaël; Colle, Isabelle; van den Bossche, Bert; de Oliveira, Claudia Pinto Marques Souza; Andraus, Wellington; Alves, Venâncio Avancini Ferreira; Leclercq, Isabelle; Vinken, Mathieu

    2016-05-01

    Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.

  18. PCSK9 Induces CD36 Degradation and Affects Long-Chain Fatty Acid Uptake and Triglyceride Metabolism in Adipocytes and in Mouse Liver.

    PubMed

    Demers, Annie; Samami, Samaneh; Lauzier, Benjamin; Des Rosiers, Christine; Ngo Sock, Emilienne Tudor; Ong, Huy; Mayer, Gaetan

    2015-12-01

    Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes the degradation of the low-density lipoprotein receptor thereby elevating plasma low-density lipoprotein cholesterol levels and the risk of coronary heart disease. Thus, the use of PCSK9 inhibitors holds great promise to prevent heart disease. Previous work found that PCSK9 is involved in triglyceride metabolism, independently of its action on low-density lipoprotein receptor, and that other yet unidentified receptors could mediate this effect. Therefore, we assessed whether PCSK9 enhances the degradation of CD36, a major receptor involved in transport of long-chain fatty acids and triglyceride storage. Overexpressed or recombinant PCSK9 induced CD36 degradation in cell lines and primary adipocytes and reduced the uptake of the palmitate analog Bodipy FL C16 and oxidized low-density lipoprotein in 3T3-L1 adipocytes and hepatic HepG2 cells, respectively. Surface plasmon resonance, coimmunoprecipitation, confocal immunofluorescence microscopy, and protein degradation pathway inhibitors revealed that PCSK9 directly interacts with CD36 and targets the receptor to lysosomes through a mechanism involving the proteasome. Importantly, the level of CD36 protein was increased by >3-fold upon small interfering RNA knockdown of endogenous PCSK9 in hepatic cells and similarly increased in the liver and visceral adipose tissue of Pcsk9(-/-) mice. In Pcsk9(-/-) mice, increased hepatic CD36 was correlated with an amplified uptake of fatty acid and accumulation of triglycerides and lipid droplets. Our results demonstrate an important role of PCSK9 in modulating the function of CD36 and triglyceride metabolism. PCSK9-mediated CD36 degradation may serve to limit fatty acid uptake and triglyceride accumulation in tissues, such as the liver. © 2015 American Heart Association, Inc.

  19. Genetic variants in desaturase gene, erythrocyte fatty acids, and risk for type 2 diabetes in Chinese Hans.

    PubMed

    Huang, Tao; Sun, Jianqin; Chen, Yanqiu; Xie, Hua; Xu, Danfeng; Huang, Jinyan; Li, Duo

    2014-01-01

    The aim of this study was to examine the association of the genetic variants in the fatty acid desaturase (FADS) gene cluster with erythrocyte phospholipid fatty acids (PLFA), and their relation to risk for type 2 diabetes mellitus (T2DM) in Han Chinese. Seven hundred and fifty-eight patients with T2DM and 400 healthy individuals were recruited. The erythrocyte PLFA and single-nucleotide polymorphism were determined by standard method. Minor allele homozygotes and heterozygotes of rs174575 and rs174537 had lower PL 20:4 ω-6 levels in healthy individuals. Minor allele homozygotes and heterozygotes of rs174455 in FADS3 gene had lower levels of 22:5 ω-3, 20:4 ω-6, and Δ5desaturase activity in patients with T2DM. Erythrocyte membrane PL 18:3 ω-3 (P for trend = 0.002), 22:5 ω-3 (P for trend < 0.001), ω-3 polyunsaturated fatty acid (P for trend < 0.001), and ω-3:ω-6 (P for trend < 0.001) were significantly inversely associated with risk for T2DM. Genetic variants in the FADS gene cluster are associated with altered erythrocyte PLFAs. High levels of PL 18:3 ω-3, 22:5 ω-3, and total ω-3 polyunsaturated fatty acid were associated with low risk for T2DM. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. 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

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

    SciTech Connect

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

    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

  2. Efficient CRISPR/Cas9 Genome Editing of Phytoene desaturase in Cassava.

    PubMed

    Odipio, John; Alicai, Titus; Ingelbrecht, Ivan; Nusinow, Dmitri A; Bart, Rebecca; Taylor, Nigel J

    2017-01-01

    CRISPR/Cas9 has become a powerful genome-editing tool for introducing genetic changes into crop species. In order to develop capacity for CRISPR/Cas9 technology in the tropical staple cassava ( Manihot esculenta ), the Phytoene desaturase ( MePDS ) gene was targeted in two cultivars using constructs carrying gRNAs targeting two sequences within MePDS exon 13. After Agrobacterium -mediated delivery of CRISPR/Cas9 reagents into cassava cells, both constructs induced visible albino phenotypes within cotyledon-stage somatic embryos regenerating on selection medium and the plants regenerated therefrom. A total of 58 (cv. 60444) and 25 (cv. TME 204) plant lines were recovered, of which 38 plant lines (19 from each cultivar) were analyzed for mutagenesis. The frequency of plant lines showing albino phenotype was high, ranging from 90 to 100% in cv. TME 204. Observed albino phenotypes were comprised of full albinos devoid of green tissue and chimeras containing a mixture of white and green tissues. Sequence analysis revealed that 38/38 (100%) of the plant lines examined carried mutations at the targeted MePDS site, with insertions, deletions, and substitutions recorded. One putatively mono-allelic homozygous line (1/19) was found from cv. 60444, while 1 (1/19) and 4 (4/19) putatively bi-allelic homozygous lines were found in 60444 and TME204, respectively. The remaining plant lines, comprised mostly of the chimeras, were found to be putatively heterozygous. We observed minor (1 bp) nucleotide substitutions and or deletions upstream of the 5' and or downstream of the 3' targeted MePDS region. The data reported demonstrates that CRISPR/Cas9-mediated genome editing of cassava is highly efficient and relatively simple, generating multi-allelic mutations in both cultivars studied. Modification of MePDS described here generates visually detectable mutated events in a relatively short time frame of 6-8 weeks, and does not require sequencing to confirm editing at the target. It

  3. A study of associations between early DHA status and fatty acid desaturase (FADS) SNP and developmental outcomes in children of obese mothers.

    PubMed

    Andersen, Karina R; Harsløf, Laurine B S; Schnurr, Theresia M; Hansen, Torben; Hellgren, Lars I; Michaelsen, Kim F; Lauritzen, Lotte

    2017-01-01

    DHA from diet or endogenous synthesis has been proposed to affect infant development, however, results are inconclusive. In this study, we aim to verify previously observed fatty acid desaturase gene cluster (FADS) SNP-specific associations with erythrocyte DHA status in 9-month-old children and sex-specific association with developmental outcomes. The study was performed in 166 children (55 % boys) of obese mothers. Erythrocyte fatty acid composition was analysed in blood-samples obtained at 9 months of age, and developmental outcomes assessed by the Ages and Stages Questionnaire at 3 years. Erythrocyte DHA level ranged from 4·4 to 9·9 % of fatty acids, but did not show any association with FADS SNP or other potential determinants. Regression analysis showed associations between erythrocyte DHA and scores for personal-social skills (β 1·8 (95 % CI 0·3, 3·3), P=0·019) and problem solving (β 3·4 (95 % CI 1·2, 5·6), P=0·003). A tendency was observed for an association in opposite direction between minor alleles (G-variant) of rs1535 and rs174575 and personal-social skills (P=0·062 and 0·068, respectively), which became significant when the SNP were combined based on their previously observed effect on erythrocyte DHA at 9 months of age (β 2·6 (95 % CI 0·01, 5·1), P=0·011). Sex-SNP interaction was indicated for rs174575 genotype on fine motor scores (P=0·016), due to higher scores among minor allele carrying girls (P=0·043), whereas no effect was seen among boys. In conclusion, DHA-increasing FADS SNP and erythrocyte DHA status were consistently associated with improved personal-social skills in this small cohort of children of obese mothers irrespective of sex, but the sample was too small to verify potential sex-specific effects.

  4. Liver (Hepatocellular) Cancer Prevention

    MedlinePlus

    ... Hepatitis C Hepatitis D Hepatitis E Hepatitis G Liver cancer is a disease in which malignant (cancer) cells ... Primary Liver Cancer Treatment Childhood Liver Cancer Treatment Liver cancer is not common in the United States. Liver ...

  5. Benign Liver Tumors

    MedlinePlus

    ... Liver Function Tests Clinical Trials Liver Transplant FAQs Medical Terminology Diseases of the Liver Alagille Syndrome Alcohol-Related ... the Liver The Progression of Liver Disease FAQs Medical Terminology HOW YOU CAN HELP Sponsorship Ways to Give ...

  6. Liver Function Tests

    MedlinePlus

    ... Liver Function Tests Clinical Trials Liver Transplant FAQs Medical Terminology Diseases of the Liver Alagille Syndrome Alcohol-Related ... the Liver The Progression of Liver Disease FAQs Medical Terminology HOW YOU CAN HELP Sponsorship Ways to Give ...

  7. Progression of Liver Disease

    MedlinePlus

    ... Liver Function Tests Clinical Trials Liver Transplant FAQs Medical Terminology Diseases of the Liver Alagille Syndrome Alcohol-Related ... the Liver The Progression of Liver Disease FAQs Medical Terminology HOW YOU CAN HELP Sponsorship Ways to Give ...

  8. Increasing dietary EPA and DHA influence estimated fatty acid desaturase activity in systemic organs which is reflected in the red blood cell in mice.

    PubMed

    Davidson, Emily A; Pickens, C Austin; Fenton, Jenifer I

    2018-03-01

    Delta-5 (D5D) and delta-6 (D6D) desaturase are key enzymes in fatty acid (FA) metabolism. Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may alter tissue FA composition via D5D and D6D. The purpose was to determine the relationship between dietary EPA + DHA, estimated desaturase activities of various tissues and the reflection of desaturase activity in the red blood cell (RBC). Mice were fed diets with increasing percent of energy from EPA + DHA. Phospholipid FA composition of heart, muscle, spleen, lung, adipose tissues and RBC were analysed. D5D and D6D enzyme activity estimates (EAE) were calculated as the ratio of 20:4/20:3 and 20:3/18:2, respectively. D5D EAE decreased in all tissues, except muscle, with increasing dietary EPA + DHA. RBC D5D EAE positively correlated with D5D EAE in all tissues. RBC D6D EAE positively correlated with muscle and inversely correlated with adipose D6D EAE. Our findings suggest differential influence of dietary EPA + DHA upon tissue desaturase activities.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  10. Stearoyl-CoA desaturase expression and fatty acid composition in milkfish (Chanos chanos) and grass carp (Ctenopharyngodon idella) during cold acclimation.

    PubMed

    Hsieh, S L; Kuo, C-M

    2005-05-01

    Desaturation of fatty acids is an important adaptation mechanism for fish to maintain membrane fluidity under thermal stress. To comprehend the temperature adaptation mechanism in fish, we investigated the difference in the changes of stearoyl-CoA desaturase expression and fatty acid composition between milkfish and grass carp under cold acclimation. We find that in both fish the proportions of unsaturated fatty acids at 15 degrees C are all higher than those at 25 degrees C. In milkfish Delta(9)-desaturation index (ratios of 16:1/16:0 and 18:1/18:0) increases significantly in the beginning of cold acclimation at 15 degrees C and decreases afterward, but in grass carp it increases slightly in the beginning of cold acclimation followed by a sustained dramatic increase. Similarly, activity of stearoyl-CoA desaturase in milkfish increases significantly in the beginning, peaks at day 4, and then decreases constantly, but in grass carp it increases gradually in the first week, rises dramatically afterward, and then maintains a very high level. The change of stearoyl-CoA desaturase activity is parallel to the change of Delta(9)-desaturation index in both milkfish and grass carp, but it is one day earlier than Delta(9)-desaturation index in milkfish. The difference of adaptation capability between milkfish and grass carp under cold stress is further evidenced by RT-PCR and Northern blot analysis of stearoyl-CoA desaturase gene expression.

  11. Heterogeneity of the Stearoyl-CoA desaturase-1 (SCD1) Gene and Metabolic Risk Factors in the EPIC-Potsdam Study

    PubMed Central

    Arregui, Maria; Buijsse, Brian; Stefan, Norbert; Corella, Dolores; Fisher, Eva; di Giuseppe, Romina; Coltell, Oscar; Knüppel, Sven; Aleksandrova, Krasimira; Joost, Hans-Georg; Boeing, Heiner; Weikert, Cornelia

    2012-01-01

    Background Stearoyl-CoA desaturase-1 (SCD1) is an enzyme involved in lipid metabolism. In mice and humans its activity has been associated with traits of the metabolic syndrome, but also with the prevention of saturated fatty acids accumulation and subsequent inflammation, whereas for liver fat content inconsistent results have been reported. Thus, variants of the gene encoding SCD1 (SCD1) could potentially modify metabolic risk factors, but few human studies have addressed this question. Methods In a sample of 2157 middle-aged men and women randomly drawn from the Potsdam cohort of the European Prospective Investigation into Cancer and Nutrition, we investigated the impact of 7 SCD1 tagging-single nucleotide polymorphisms (rs1502593, rs522951, rs11190480, rs3071, rs3793767, rs10883463 and rs508384) and 5 inferred haplotypes with frequency >5% describing 90.9% of the genotype combinations in our population, on triglycerides, body mass index (BMI), waist circumference (WC), glycated haemoglobin (HbA1c), high-sensitivity C-reactive protein (hs-CRP), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT) and fetuin-A. Results No significant associations between any of the SNPs or haplotypes and BMI, WC, fetuin-A and hs-CRP were observed. Associations of rs10883463 with triglycerides, GGT and HbA1c as well as of rs11190480 with ALT activity, were weak and became non-significant after multiple-testing correction. Also associations of the haplotype harbouring the minor allele of rs1502593 with HbA1c levels, the haplotype harbouring the minor alleles of rs11190480 and rs508384 with activity of ALT, and the haplotype harbouring the minor alleles of rs522951, rs10883463 and rs508384 with triglyceride and HbA1C levels and GGT activities did not withstand multiple-testing correction. Conclusion These findings suggest that there are no associations between common variants of SCD1 or its inferred haplotypes and the investigated metabolic risk factors. However, given

  12. Elucidation of the sex-pheromone biosynthesis producing 5,7-dodecadienes in Dendrolimus punctatus (Lepidoptera: Lasiocampidae) reveals Delta 11- and Delta 9-desaturases with unusual catalytic properties.

    PubMed

    Liénard, Marjorie A; Lassance, Jean-Marc; Wang, Hong-Lei; Zhao, Cheng-Hua; Piskur, Jure; Johansson, Tomas; Löfstedt, Christer

    2010-06-01

    Sex pheromones produced by female moths of the Lasiocampidae family include conjugated 5,7-dodecadiene components with various oxygenated terminal groups. Here we describe the molecular cloning, heterologous expression and functional characterization of desaturases associated with the biosynthesis of these unusual chemicals. By homology-based PCR screening we characterized five cDNAs from the female moth pheromone gland that were related to other moth desaturases, and investigated their role in the production of the (Z)-5-dodecenol and (Z5,E7)-dodecadienol, major pheromone constituents of the pine caterpillar moth, Dendrolimus punctatus. Functional expression of two desaturase cDNAs belonging to the Delta 11-subfamily, Dpu-Delta 11(1)-APSQ and Dpu-Delta 11(2)-LPAE, showed that they catalysed the formation of unsaturated fatty acyls (UFAs) that can be chain-shortened by beta-oxidation and subsequently reduced to the alcohol components. A first (Z)-11-desaturation step is performed by Dpu-Delta 11(2)-LPAE on stearic acid that leads to (Z)-11-octadecenoic acyl, which is subsequently chain shortened to the (Z)-5-dodecenoic acyl precursor. The Dpu-Delta 11(1)-APSQ desaturase had the unusual property of producing Delta 8 mono-UFA of various chain lengths, but not when transformed yeast were grown in presence of (Z)-9-hexadecenoic acyl, in which case the biosynthetic intermediate (Z9,E11)-hexadecadienoic UFA was produced. In addition to a typical Z9 activity, a third transcript, Dpu-Delta 9-KPSE produced E9 mono-UFAs of various chain lengths. When provided with the (Z)-7-tetradecenoic acyl, it formed the (Z7,E9)-tetradecadienoic UFA, another biosynthetic intermediate that can be chain-shortened to (Z5,E7)-dodecadienoic acyl. Both Dpu-Delta 11(1)-APSQ and Dpu-Delta 9-KPSE thus exhibited desaturase activities consistent with the biosynthesis of the dienoic precursor. The combined action of three desaturases in generating a dienoic sex-pheromone component emphasizes the

  13. Fatty Liver

    MedlinePlus

    ... Drug Information, Search Drug Names, Generic and Brand Natural Products, ... fat to accumulate in liver cells by causing the body to synthesize more fat or by processing (metabolizing) and excreting fat more slowly. As a ...

  14. Liver biopsy

    MedlinePlus

    ... Primary biliary cirrhosis Primary biliary cholangitis Pyogenic liver abscess Reye syndrome Sclerosing cholangitis Wilson disease Risks Risks may include: Collapsed lung Complications from the sedation Injury to the gallbladder ...

  15. An N-terminal di-proline motif is essential for fatty acid–dependent degradation of Δ9-desaturase in Drosophila

    PubMed Central

    Murakami, Akira; Nagao, Kohjiro; Juni, Naoto; Hara, Yuji; Umeda, Masato

    2017-01-01

    The Δ9-fatty acid desaturase introduces a double bond at the Δ9 position of the acyl moiety of acyl-CoA and regulates the cellular levels of unsaturated fatty acids. However, it is unclear how Δ9-desaturase expression is regulated in response to changes in the levels of fatty acid desaturation. In this study, we found that the degradation of DESAT1, the sole Δ9-desaturase in the Drosophila cell line S2, was significantly enhanced when the amounts of unsaturated acyl chains of membrane phospholipids were increased by supplementation with unsaturated fatty acids, such as oleic and linoleic acids. In contrast, inhibition of DESAT1 activity remarkably suppressed its degradation. Of note, removal of the DESAT1 N-terminal domain abolished the responsiveness of DESAT1 degradation to the level of fatty acid unsaturation. Further truncation and amino acid replacement analyses revealed that two sequential prolines, the second and third residues of DESAT1, were responsible for the unsaturated fatty acid–dependent degradation. Although degradation of mouse stearoyl-CoA desaturase 1 (SCD1) was unaffected by changes in fatty acid unsaturation, introduction of the N-terminal sequential proline residues into SCD1 conferred responsiveness to unsaturated fatty acid–dependent degradation. Furthermore, we also found that the Ca2+-dependent cysteine protease calpain is involved in the sequential proline–dependent degradation of DESAT1. In light of these findings, we designated the sequential prolines at the second and third positions of DESAT1 as a “di-proline motif,” which plays a crucial role in the regulation of Δ9-desaturase expression in response to changes in the level of cellular unsaturated fatty acids. PMID:28972163

  16. Iron homeostasis in the liver

    PubMed Central

    Anderson, Erik R; Shah, Yatrik M

    2014-01-01

    Iron is an essential nutrient that is tightly regulated. A principal function of the liver is the regulation of iron homeostasis. The liver senses changes in systemic iron requirements and can regulate iron concentrations in a robust and rapid manner. The last 10 years have led to the discovery of several regulatory mechanisms in the liver which control the production of iron regulatory genes, storage capacity, and iron mobilization. Dysregulation of these functions leads to an imbalance of iron, which is the primary causes of iron-related disorders. Anemia and iron overload are two of the most prevalent disorders worldwide and affect over a billion people. Several mutations in liver-derived genes have been identified, demonstrating the central role of the liver in iron homeostasis. During conditions of excess iron, the liver increases iron storage and protects other tissues, namely the heart and pancreas from iron-induced cellular damage. However, a chronic increase in liver iron stores results in excess reactive oxygen species production and liver injury. Excess liver iron is one of the major mechanisms leading to increased steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. PMID:23720289

  17. Factors Affecting the Development of an Antibody Response to Hepatitis B Immunization in Children With Intestinal Failure: Before and After Small Bowel Transplantation (With and Without Liver Graft).

    PubMed

    Craggs, Helen M; Jackson, Phoebe; Gupte, Girish; Hartley, Jane; Abdel-Hady, Mona; Morton, Rachael; Beath, Sue; Hogg, Lindsay

    2017-08-01

    Small bowel transplant with or without a liver graft (SBTx ± LTx) for children with intestinal failure involves checking their immunity to a range of microorganisms, including hepatitis B virus (HBV), at the time of assessment. HBV vaccination in the United Kingdom is recommended for transplant candidates. The aim of this audit was to find out how many SBTx ± LTx candidates received HBV vaccination before transplantation and how the timing of vaccination influenced the development of immunity. Retrospective review of case notes and hospital microbiology database formed the basis of the study. Vaccination history and serology were available in 56 of 87 subjects who had SBTx ± LTx. All patients were seronegative for HBV when assessed for transplant. HBV vaccination was started before transplant in 25 children and after transplant in 31. Eight children died posttransplant before their immunity could be checked, but of the 48 survivors, 20 children developed immunity, of whom 13 (65%) received at least 1 vaccination before SBTx ± LTx ( P = .008). Lack of response to HBV vaccine was significantly associated with isolated bowel transplantation and intensification of immune suppression. Of 11 children, 5 lost hepatitis B surface antibody (HbsAb), and 28 never made HBsAb, despite repeated vaccinations. Our study clearly shows that HBV vaccine before transplant is more effective. In line with renal failure patients, we suggest that children with chronic intestinal failure receive HBV vaccine when clinically stable, before referral for transplant. Higher-dose vaccines, accelerated schedules, and more frequent booster vaccinations are also strategies that may improve HBsAb levels after transplant.

  18. Adverse events affect sorafenib efficacy in patients with recurrent hepatocellular carcinoma after liver transplantation: experience at a single center and review of the literature.

    PubMed

    Zavaglia, Claudio; Airoldi, Aldo; Mancuso, Andrea; Vangeli, Marcello; Viganò, Raffaella; Cordone, Gabriella; Gentiluomo, Maria; Belli, Luca Saverio

    2013-02-01

    The aim of this study was to assess the safety and efficacy of sorafenib, with or without everolimus, in the treatment of recurrent hepatocellular carcinoma (HCC) after an orthotopic liver transplantation (OLT). We reviewed the outcome of our consecutive cohort series of patients. Eleven patients (nine men) with recurrent HCC after OLT were treated. Four patients received cyclosporine plus sorafenib at a starting dose of 400 mg twice daily; seven received the combination of sorafenib (same dosage) and everolimus. Sorafenib was reduced or stopped according to the drug label. The median time to recurrence was 12 months (range 2-66). The mean age at the start of treatment was 57 ± 9 years. Sorafenib was withdrawn because of intolerance or side-effects in four (36%) patients. Dose reduction because of adverse events or intolerance was required in 91% of patients after 26 ± 11 days from the start of treatment. The average length of treatment was 68 days (range 15-444). One patient died because of a massive gastrointestinal bleeding while receiving sorafenib and everolimus. The most frequent adverse events were fatigue (54%), skin toxicity (45%), and hypophosphatemia (36%). Two patients (18%) showed a radiological partial response, one (9%) had a stable disease, and six (54%) showed a progressive disease. None of the patients achieved a complete response. Treatment response could not be assessed in two (18%) patients. The overall median survival since the start of treatment was 5 months. One-year survival was 18%. Sorafenib, with or without mammalian target of rapamycin inhibitors, is poorly tolerated and rarely effective in the treatment of recurrent HCC after OLT.

  19. Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

    SciTech Connect

    Xing, Xiaomang; Li, Danyang; Chen, Dilong

    Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose,more » insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty

  20. The Mycobacterium tuberculosis desaturase DesA1 (Rv0824c) is a Ca{sup 2+} binding protein

    SciTech Connect

    Yeruva, Veena C., E-mail: veenachaitanya@ccmb.res.in; Savanagouder, Mamata; Khandelwal, Radhika

    The hallmark feature of Mycobacterium tuberculosis (M.tb) the causative agent of human tuberculosis, is its complex lipid rich cell wall comprised primarily of mycolic acids, long chain fatty acids that play a key role in structural stability and permeability of the cell wall. In addition, they are involved in inhibiting phagosome-lysosome fusion and aid in granuloma formation during the pathogenic process. M.tb DesA1 is an essential acyl-acyl carrier protein desaturase predicted to catalyze the introduction of position specific double bonds during the biosynthesis of mycolic acids. This protein is one among three annotated desaturases (DesA1-3) in the M.tb genome butmore » is unique in containing a βγ-crystallin Greek key signature motif, a well-characterized fold known to mediate Ca{sup 2+} binding in both prokaryotic and eukaryotic organisms. Using Isothermal Titration Calorimetry and {sup 45}CaCl{sub 2} overlay, we demonstrate that Ca{sup 2+} binds to DesA1. Spectroscopic measurements suggested that this binding induces changes in protein conformation but does not lead to significant alterations in the secondary structure of the protein, a feature common to several βγ-crystallins. An M. smegmatis strain over-expressing M.tb desA1 showed a Ca{sup 2+} dependent variation in surface phenotype, revealing a functional role for Ca{sup 2+}in DesA1 activity. This study represents the first identification of a Ca{sup 2+} binding βγ-crystallin in M.tb, emphasizing the implicit role of Ca{sup 2+} in the pathogenesis of M.tb. - Highlights: • Mycobacterium tuberculosis DesA1 is an essential acyl-ACP desaturase. • DesA1 was identified to contain a βγ-crystallin Greek key signature motif. • Ca{sup 2+} binds to DesA1 with an affinity of 53 μM and induces changes in its conformation. • M. smegmatis overexpressing M.tb DesA1 shows a Ca{sup 2+} dependent phenotype. • Targetting the Ca{sup 2+} dependent function of DesA1 could be of therapeutic value.« less

  1. The caspase-3/p120 RasGAP stress-sensing module reduces liver cancer incidence but does not affect overall survival in gamma-irradiated and carcinogen-treated mice.

    PubMed

    Vanli, Güliz; Sempoux, Christine; Widmann, Christian

    2017-06-01

    Activation of oncogenes is the initial step in cellular transformation. Oncogenes favor aberrant proliferation, which, at least initially, induces cellular stress. This oncogenic stress can act as a safeguard mechanism against further transformation by inducing senescence or apoptosis. Yet, the few premalignant cells that tolerate and escape these senescent or apoptotic responses are those that will ultimately generate tumors. The caspase-3/p120 RasGAP module is a stress-sensing device that promotes survival under mild stress conditions. A point mutation in RasGAP that prevents its cleavage by caspase-3 inactivates the pro-survival capacity of the device. When the mice homozygous for this mutation (D455A knock-in mice) are patho-physiologically challenged, they experience much stronger cellular damage than their wild-type counterparts and the affected organs rapidly lose their functionality. We reasoned that the caspase-3/p120 RasGAP module could help premalignant cells to cope with oncogenic stress and hence favor the development of tumors. Using gamma-irradiation and N-ethyl-N-nitrosourea (ENU) as tumor initiators, we assessed the survival advantage that the caspase-3/p120 RasGAP module could provide to premalignant cells. No difference in overall mortality between wild-type and D455A knock-in mice were observed. However, the number of ENU-induced liver tumors in the knock-in mice was higher than in control mice. These results indicate that the caspase-3/p120 RasGAP stress-sensing module impacts on carcinogen-induced liver cancer incidence but not sufficiently so as to affect overall survival. Hence, gamma irradiation and ENU-induced tumorigenesis processes do not critically rely on a survival mechanism that contributes to the maintenance of organ homeostasis in stressed healthy tissues. © 2017 Wiley Periodicals, Inc.

  2. Inhibitors of dihydroceramide desaturase 1: Therapeutic agents and pharmacological tools to decipher the role of dihydroceramides in cell biology.

    PubMed

    Casasampere, Mireia; Ordoñez, Yadira F; Pou, Ana; Casas, Josefina

    2016-05-01

    Dihydroceramide desaturase (Des1) is the last enzyme in the de novo synthesis of ceramides (Cer). It catalyzes the insertion of a double bond into dihydroceramides (dhCer) to convert them to Cer, both of which are further metabolized to more complex (dihydro) sphingolipids. For many years dhCer have received poor attention, mainly due to their supposed lack of biological activity. It was not until about ten years ago that the concept that dhCer might have regulatory roles in biology emerged for the first time. Since then, multiple publications have established that dhCer are implicated in a wide spectrum of biological processes. Physiological and pathophysiological functions of dhCer have been recently reviewed. In this review we will focus on the biochemical features of Des1 and on its inhibition by different compounds with presumably different modes of action. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Elevated stearoyl-CoA desaturase-1 expression in skeletal muscle contributes to abnormal fatty acid partitioning in obese humans.

    PubMed

    Hulver, Matthew W; Berggren, Jason R; Carper, Michael J; Miyazaki, Makoto; Ntambi, James M; Hoffman, Eric P; Thyfault, John P; Stevens, Robert; Dohm, G Lynis; Houmard, Joseph A; Muoio, Deborah M

    2005-10-01

    Obesity and type 2 diabetes are strongly associated with abnormal lipid metabolism and accumulation of intramyocellular triacylglycerol, but the underlying cause of these perturbations are yet unknown. Herein, we show that the lipogenic gene, stearoyl-CoA desaturase 1 (SCD1), is robustly up-regulated in skeletal muscle from extremely obese humans. High expression and activity of SCD1, an enzyme that catalyzes the synthesis of monounsaturated fatty acids, corresponded with low rates of fatty acid oxidation, increased triacylglycerol synthesis and increased monounsaturation of muscle lipids. Elevated SCD1 expression and abnormal lipid partitioning were retained in primary skeletal myocytes derived from obese compared to lean donors, implying that these traits might be driven by epigenetic and/or heritable mechanisms. Overexpression of human SCD1 in myotubes from lean subjects was sufficient to mimic the obese phenotype. These results suggest that elevated expression of SCD1 in skeletal muscle contributes to abnormal lipid metabolism and progression of obesity.

  4. Pinworm infection masquerading as colorectal liver metastasis.

    PubMed

    Roberts, K J; Hubscher, S; Mangat, K; Sutcliffe, R; Marudanayagam, R

    2012-09-01

    Enterobius vermicularis is responsible for a variety of diseases but rarely affects the liver. Accurate characterisation of suspected liver metastases is essential to avoid unnecessary surgery. In the presented case, following a diagnosis of rectal cancer, a solitary liver nodule was diagnosed as a liver metastasis due to typical radiological features and subsequently resected. At pathological assessment, however, a necrotic nodule containing E. vermicularis was identified. Solitary necrotic nodules of the liver are usually benign but misdiagnosed frequently as malignant due to radiological features. It is standard practice to diagnose colorectal liver metastases solely on radiological evidence. Without obtaining tissue prior to liver resection, misdiagnosis of solitary necrotic nodules of the liver will continue to occur.

  5. Pinworm infection masquerading as colorectal liver metastasis

    PubMed Central

    Roberts, KJ; Hubscher, S; Mangat, K; Sutcliffe, R; Marudanayagam, R

    2012-01-01

    Enterobius vermicularis is responsible for a variety of diseases but rarely affects the liver. Accurate characterisation of suspected liver metastases is essential to avoid unnecessary surgery. In the presented case, following a diagnosis of rectal cancer, a solitary liver nodule was diagnosed as a liver metastasis due to typical radiological features and subsequently resected. At pathological assessment, however, a necrotic nodule containing E vermicularis was identified. Solitary necrotic nodules of the liver are usually benign but misdiagnosed frequently as malignant due to radiological features. It is standard practice to diagnose colorectal liver metastases solely on radiological evidence. Without obtaining tissue prior to liver resection, misdiagnosis of solitary necrotic nodules of the liver will continue to occur. PMID:22943320

  6. Expression and functional characterization of a C-7 cholesterol desaturase from Tetrahymena thermophila in an insect cell line.

    PubMed

    Poklepovich, Tomas J; Urtasun, Nicolás; Miranda, María V; Nusblat, Alejandro D; Nudel, Clara B

    2015-04-01

    Tetrahymena thermophila transforms exogenous cholesterol into pro-vitamin D3 (7-dehydrocholesterol) with remarkable efficiency in a one-step reaction carried out by a C-7 cholesterol desaturase. The enzyme DES7 is encoded by the gene TTHERM_00310640, identified with RNAi and gene knock-out experiments, but has not yet been heterologously expressed actively in any organism. A model derived from its amino acid sequence classified DES7p as a Rieske-type oxygenase with transmembrane localization. The protein has catalytic activity, sequence and topological similarity to DAF-36/Neverland proteins involved in the synthesis of steroid hormones in insects and nematodes. Due to their structural and functional similarity, we analyzed the expression of a codon optimized DES7 gene from Tetrahymena in the insect Sf9 cell line, identified and measured the steroid metabolites formed, and extended the actual knowledge on its localization. We found that the accumulation of 7-dehydrocholesterol could be increased 16-40-fold in Spodopterafrugiperda, depending on physiological conditions, by overexpression of T. thermophila DES7. The protein was detected in the microsomal fraction, in accordance with previous reports. Although the electron transfer chain for Des7p/DAF-36/Neverland Rieske-type oxygenases is presently unknown, we identified possible donors in the ciliate and insect genomes by bioinformatic analysis. In spite of the large evolutionary distance between S. frugiperda and T. thermophila, the results indicate that there is significant functional conservation of the electron donors, since the ciliate's sterol desaturase can function in the context of the insect electron transport system. The results achieved demonstrate that DES7 is the first gene from a ciliate, coding for a microsomal enzyme, expressed in active form in an insect cell line. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. 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.

    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 isoformmore » 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.« less

  8. Omega-6 polyunsaturated fatty acids, serum zinc, delta-5- and delta-6-desaturase activities and incident metabolic syndrome.

    PubMed

    Yary, T; Voutilainen, S; Tuomainen, T-P; Ruusunen, A; Nurmi, T; Virtanen, J K

    2017-08-01

    The associations of n-6 polyunsaturated fatty acids (PUFA) with metabolic syndrome have been poorly explored. We investigated the associations of the serum n-6 PUFA and the activities of enzymes involved in the PUFA metabolism, delta-5-desaturase (D5D) and delta-6-desaturase (D6D) with risk of incident metabolic syndrome. We also investigated whether zinc, a cofactor for these enzymes, modifies these associations. A prospective follow-up study was conducted on 661 men who were aged 42-60 years old at baseline in 1984-1989 and who were re-examined in 1998-2001. Men in the highest versus the lowest serum total omega-6 PUFA tertile had a 70% lower multivariate-adjusted risk of incident metabolic syndrome [odds ratio (OR) = 0.30; 95% confidence interval (CI) = 0.18-0.51, P trend < 0.001]. Inverse associations were also observed for linoleic acid, arachidonic acid and D5D activity. By contrast, men in the highest tertile of D6D activity had an 84% higher risk (OR = 1.84; 95% CI = 1.15-2.94, P trend = 0.008). Similar associations were observed with many of the metabolic syndrome components at the re-examinations. Most associations were attenuated after adjustment for body mass index. Finally, the associations of D6D and LA were stronger among those with a higher serum zinc concentration. Higher serum total n-6 PUFA, linoleic acid and arachidonic acid concentrations and D5D activity were associated with a lower risk of developing metabolic syndrome and higher D6D activity was associated with a higher risk. The role of zinc also needs to be investigated in other populations. © 2016 The British Dietetic Association Ltd.

  9. The antiestrogen endoxifen protects rat liver mitochondria from permeability transition pore opening and oxidative stress at concentrations that do not affect the phosphorylation efficiency

    SciTech Connect

    Ribeiro, Mariana P.C.; Silva, Filomena S.G.; Santos, Armanda E.

    2013-02-15

    Endoxifen (EDX) is a key active metabolite of tamoxifen (TAM) with higher affinity and specificity to estrogen receptors that also inhibits aromatase activity. It is safe and well tolerated by healthy humans, but its use requires toxicological characterization. In this study, the effects of EDX on mitochondria, the primary targets for xenobiotic-induced toxicity, were monitored to clarify its potential side effects. EDX up to 30 nmol/mg protein did not affect the mitochondrial oxidative phosphorylation. At 50 nmol EDX/mg protein, EDX decreased the ADP phosphorylation rate and a partial collapse of mitochondrial membrane potential (Δψ), that parallels a state 4 stimulation,more » was observed. As the stimulation of state 4 was not inhibited by oligomycin and 50 nmol EDX/mg protein caused a slight decrease in the light scattering of mitochondria, these data suggest that EDX promotes membrane permeabilization to protons, whereas TAM at the same concentration induced mitochondrial membrane disruption. Moreover, EDX at 10 nmol/mg protein prevented and reversed the Ca{sup 2+}-induced depolarization of ΔΨ and the release of mitochondrial Ca{sup 2+}, similarly to cyclosporine A, indicating that EDX did not affect Ca{sup 2+} uptake, but directly interfered with the proteins of the mitochondrial permeability transition (MPT) megacomplex, inhibiting MPT induction. At this concentration, EDX exhibited antioxidant activity that may account for the protective effect against MPT pore opening. In conclusion, EDX within the range of concentrations reached in tissues did not significantly damage the bioenergetic functions of mitochondria, contrarily to the prodrug TAM, and prevented the MPT pore opening and the oxidative stress in mitochondria, supporting that EDX may be a less toxic drug for women with breast carcinoma. - Highlights: ► Mitochondria are important targets of Endoxifen. ► Endoxifen prevents mitochondrial permeability transition. ► Endoxifen prevents

  10. 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.

  11. Hepatic (Liver) Function Panel

    MedlinePlus

    ... Educators Search English Español Blood Test: Hepatic (Liver) Function Panel KidsHealth / For Parents / Blood Test: Hepatic (Liver) ... kidneys ) is working. What Is a Hepatic (Liver) Function Panel? A liver function panel is a blood ...

  12. Liver disease - resources

    MedlinePlus

    Resources - liver disease ... The following organizations are good resources for information on liver disease : American Liver Foundation -- www.liverfoundation.org Children's Liver Association for Support Services (C.L.A.S.S.) -- www. ...

  13. Elevated Liver Enzymes

    MedlinePlus

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  14. Fads1 and 2 are promoted to meet instant need for long-chain polyunsaturated fatty acids in goose fatty liver.

    PubMed

    Osman, Rashid H; Liu, Long; Xia, Lili; Zhao, Xing; Wang, Qianqian; Sun, Xiaoxian; Zhang, Yihui; Yang, Biao; Zheng, Yun; Gong, Daoqing; Geng, Tuoyu

    2016-07-01

    Global prevalence of non-alcoholic fatty liver disease (NAFLD) constitutes a threat to human health. Goose is a unique model of NAFLD for discovering therapeutic targets as its liver can develop severe steatosis without overt injury. Fatty acid desaturase (Fads) is a potential therapeutic target as Fads expression and mutations are associated with liver fat. Here, we hypothesized that Fads was promoted to provide a protection for goose fatty liver. To test this, goose Fads1 and Fads2 were sequenced. Fads1/2/6 expression was determined in goose liver and primary hepatocytes by quantitative PCR. Liver fatty acid composition was also analyzed by gas chromatography. Data indicated that hepatic Fads1/2/6 expression was gradually increased with the time of overfeeding. In contrast, trans-C18:1n9 fatty acid (Fads inhibitor) was reduced. However, enhanced Fads capacity for long-chain polyunsaturated fatty acid (LC-PUFA) synthesis was not sufficient to compensate for the depleted LC-PUFAs in goose fatty liver. Moreover, cell studies showed that Fads1/2/6 expression was regulated by fatty liver-associated factors. Together, these findings suggest Fads1/2 as protective components are promoted to meet instant need for LC-PUFAs in goose fatty liver, and we propose this is required for severe hepatic steatosis without liver injury.

  15. Evaluation of abnormal liver function tests.

    PubMed

    Agrawal, Swastik; Dhiman, Radha K; Limdi, Jimmy K

    2016-04-01

    Incidentally detected abnormality in liver function tests is a common situation encountered by physicians across all disciplines. Many of these patients do not have primary liver disease as most of the commonly performed markers are not specific for the liver and are affected by myriad factors unrelated to liver disease. Also, many of these tests like liver enzyme levels do not measure the function of the liver, but are markers of liver injury, which is broadly of two types: hepatocellular and cholestatic. A combination of a careful history and clinical examination along with interpretation of pattern of liver test abnormalities can often identify type and aetiology of liver disease, allowing for a targeted investigation approach. Severity of liver injury is best assessed by composite scores like the Model for End Stage Liver Disease rather than any single parameter. In this review, we discuss the interpretation of the routinely performed liver tests along with the indications and utility of quantitative tests. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. The Crystal Structure of the Ivy delta4-16:0-ACP Desaturase Reveals Structural Details of the Oxidized Active Site and Potential Determinants of Regioselectivity

    SciTech Connect

    Guy,J.; Whittle, E.; Kumaran, D.

    2007-01-01

    The multifunctional acyl-acyl carrier protein (ACP) desaturase from Hedera helix (English ivy) catalyzes the {Delta}{sup 4} desaturation of 16:0-ACP and the{Delta}{sup 9} desaturation of 18:0-ACP and further desaturates{Delta}{sup 9}-16:1 or {Delta}{sup 9}-18:1 to the corresponding {Delta}{sup 4,9} dienes. The crystal structure of the enzyme has been solved to 1.95{angstrom} resolution, and both the iron-iron distance of 3.2{angstrom} and the presence of a {mu}-oxo bridge reveal this to be the only reported structure of a desaturase in the oxidized FeIII-FeIII form. Significant differences are seen between the oxidized active site and the reduced active site of the Ricinus communis (castor) desaturase;more » His{sup 227} coordination to Fe2 is lost, and the side chain of Glu{sup 224}, which bridges the two iron ions in the reduced structure, does not interact with either iron. Although carboxylate shifts have been observed on oxidation of other diiron proteins, this is the first example of the residue moving beyond the coordination range of both iron ions. Comparison of the ivy and castor structures reveal surface amino acids close to the annulus of the substrate-binding cavity and others lining the lower portion of the cavity that are potential determinants of their distinct substrate specificities. We propose a hypothesis that differences in side chain packing explains the apparent paradox that several residues lining the lower portion of the cavity in the ivy desaturase are bulkier than their equivalents in the castor enzyme despite the necessity for the ivy enzyme to accommodate three more carbons beyond the diiron site.« less

  17. The Cytochrome b5 dependent C-5(6) sterol desaturase DES5A from the endoplasmic reticulum of Tetrahymena thermophila complements ergosterol biosynthesis mutants in Saccharomyces cerevisiae

    PubMed Central

    Poklepovich, Tomas J.; Rinaldi, Mauro A.; Tomazic, Mariela L.; Favale, Nicolas O.; Turkewitz, Aaron P.; Nudel, Clara B.; Nusblat, Alejandro D.

    2012-01-01

    Tetrahymena thermophila is a free-living ciliate with no exogenous sterol requirement. However, it can perform several modifications on externally added sterols including desaturation at C5(6), C7(8), and C22(23). Sterol desaturases in Tetrahymena are microsomal enzymes that require Cyt b5, Cyt b5 reductase, oxygen, and reduced NAD(P)H for their activity, and some of the genes encoding these functions have recently been identified. The DES5A gene encodes a C-5(6) sterol desaturase, as shown by gene knockout in Tetrahymena. To confirm and extend that result, and to develop new approaches to gene characterization in Tetrahymena, we have now, expressed DES5A in Saccharomyces cerevisiae. The DES5A gene was codon optimized and expressed in a yeast mutant, erg3Δ, which is disrupted for the gene encoding the S. cerevisiae C-5(6) sterol desaturase ERG3. The complemented strain was able to accumulate 74% of the wild type level of ergosterol, and also lost the hypersensitivity to cycloheximide associated with the lack of ERG3 function. C-5(6) sterol desaturases are expected to function at the endoplasmic reticulum. Consistent with this, a GFP-tagged copy of Des5Ap was localized to the endoplasmic reticulum in both Tetrahymena and yeast. This work shows for the first time that both function and localization are conserved for a microsomal enzyme between ciliates and fungi, notwithstanding the enormous evolutionary distance between these lineages. The results suggest that heterologous expression of ciliate genes in S. cerevisiae provides a useful tool for the characterization of genes in Tetrahymena, including genes encoding membrane protein complexes. PMID:22982564

  18. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Differential Contribution of Endoplasmic Reticulum and Chloroplast ω-3 Fatty Acid Desaturase Genes to the Linolenic Acid Content of Olive (Olea europaea) Fruit.

    PubMed

    Hernández, M Luisa; Sicardo, M Dolores; Martínez-Rivas, José M

    2016-01-01

    Linolenic acid is a polyunsaturated fatty acid present in plant lipids, which plays key roles in plant metabolism as a structural component of storage and membrane lipids, and as a precursor of signaling molecules. The synthesis of linolenic acid is catalyzed by two different ω-3 fatty acid desaturases, which correspond to microsomal- (FAD3) and chloroplast- (FAD7 and FAD8) localized enzymes. We have investigated the specific contribution of each enzyme to the linolenic acid content in olive fruit. With that aim, we isolated two different cDNA clones encoding two ω-3 fatty acid desaturases from olive (Olea europaea cv. Picual). Sequence analysis indicates that they code for microsomal (OepFAD3B) and chloroplast (OepFAD7-2) ω-3 fatty acid desaturase enzymes, different from the previously characterized OekFAD3A and OekFAD7-1 genes. Functional expression in yeast of the corresponding OepFAD3A and OepFAD3B cDNAs confirmed that they encode microsomal ω-3 fatty acid desaturases. The linolenic acid content and transcript levels of olive FAD3 and FAD7 genes were measured in different tissues of Picual and Arbequina cultivars, including mesocarp and seed during development and ripening of olive fruit. Gene expression and lipid analysis indicate that FAD3A is the gene mainly responsible for the linolenic acid present in the seed, while FAD7-1 and FAD7-2 contribute mostly to the linolenic acid present in the mesocarp and, therefore, in the olive oil. These results also indicate the relevance of lipid trafficking between the endoplasmic reticulum and chloroplast in determining the linolenic acid content of membrane and storage lipids in oil-accumulating photosynthetic tissues. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Rapid, transient, and highly localized induction of plastidial ω-3 fatty acid desaturase mRNA at fungal infection sites in Petroselinum crispum

    PubMed Central

    Kirsch, Christoph; Takamiya-Wik, Monica; Reinold, Susanne; Hahlbrock, Klaus; Somssich, Imre E.

    1997-01-01

    Parsley (Petroselinum crispum) plants and suspension-cultured cells have been used extensively for studies of non-host-resistance mechanisms in plant/pathogen interactions. We now show that treatment of cultured parsley cells with a defined peptide elicitor of fungal origin causes rapid and large changes in the levels of various unsaturated fatty acids. While linoleic acid decreased and linolenic acid increased steadily for several hours, comparatively sharp increases in oleic acid followed a biphasic time course. In contrast, the overall level of stearic acid remained unaffected. Using a PCR-based approach, a parsley cDNA was isolated sharing high sequence similarity with ω-3 fatty acid desaturases. Subsequent isolation and characterization of a full-length cDNA enabled its functional identification as a plastid-localized ω-3 fatty acid desaturase by complementation of the Arabidopsis thaliana fad7/8 double mutant which is low in trienoic fatty acids. ω-3 Fatty acid desaturase mRNA accumulated rapidly and transiently in elicitor-treated cultured parsley cells, protoplasts, and leaves, as well as highly localized around fungal infection sites in parsley leaf buds. These results indicate that unsaturated fatty acid metabolism is yet another component of the highly complex, transcriptionally regulated pathogen defense response in plants. PMID:9050908

  1. Maternal single nucleotide polymorphisms in the fatty acid desaturase 1 and 2 coding regions modify the impact of prenatal supplementation with DHA on birth weight.

    PubMed

    Gonzalez-Casanova, Ines; Rzehak, Peter; Stein, Aryeh D; Garcia Feregrino, Raquel; Rivera Dommarco, Juan A; Barraza-Villarreal, Albino; Demmelmair, Hans; Romieu, Isabelle; Villalpando, Salvador; Martorell, Reynaldo; Koletzko, Berthold; Ramakrishnan, Usha

    2016-04-01

    Specific single nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene affect the activity and efficiency of enzymes that are responsible for the conversion of polyunsaturated fatty acids (PUFAs) into their long-chain active form. A high prevalence of SNPs that are associated with slow PUFA conversion has been described in Hispanic populations. We assessed the heterogeneity of the effect of prenatal supplementation with docosahexaenoic acid (DHA) on birth weight across selected FADS SNPs in a sample of Mexican women and their offspring. We obtained information on the maternal genotype from stored blood samples of 654 women who received supplementation with 400 mg DHA/d or a placebo from weeks 18 to 22 of gestation through delivery as part of a randomized controlled trial conducted in Cuernavaca, Mexico. We selected 4 tag SNPs (rs174455, rs174556, rs174602, and rs498793) in the FADS region for analysis. We used an ANOVA to test for the heterogeneity of the effect on birth weight across each of the 4 SNPs. The mean ± SD birth weight was 3210 ± 470 g, and the weight-for-age z score (WAZ) was -0.24 ± 1.00. There were no intention-to-treat differences in birth weights. We showed significant heterogeneity by SNP rs174602 (P= 0.02); offspring of carriers of alleles TT and TC in the intervention group were heavier than those in the placebo group (WAZ: -0.13 ± 0.14 and -0.20 ± 0.08 compared with -0.55 ± 0.15 and -0.39 ± 0.09, respectively); there were no significant differences in offspring of rs174602 CC homozygotes (WAZ: -0.26 ± 0.09 in the intervention group compared with -0.04 ± 0.09 in the placebo group). We showed no significant heterogeneity across the other 3 FADS SNPs. Differential responses to prenatal DHA supplementation on the basis of the genetic makeup of target populations could explain the mixed evidence of the impact of DHA supplementation on birth weight. This trial was registered at clinicaltrials.gov as NCT00646360. © 2016

  2. Maternal single nucleotide polymorphisms in the fatty acid desaturase 1 and 2 coding regions modify the impact of prenatal supplementation with DHA on birth weight12

    PubMed Central

    Gonzalez-Casanova, Ines; Rzehak, Peter; Stein, Aryeh D; Garcia Feregrino, Raquel; Dommarco, Juan A Rivera; Barraza-Villarreal, Albino; Demmelmair, Hans; Romieu, Isabelle; Villalpando, Salvador; Martorell, Reynaldo; Koletzko, Berthold; Ramakrishnan, Usha

    2016-01-01

    Background: Specific single nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene affect the activity and efficiency of enzymes that are responsible for the conversion of polyunsaturated fatty acids (PUFAs) into their long-chain active form. A high prevalence of SNPs that are associated with slow PUFA conversion has been described in Hispanic populations. Objective: We assessed the heterogeneity of the effect of prenatal supplementation with docosahexaenoic acid (DHA) on birth weight across selected FADS SNPs in a sample of Mexican women and their offspring. Design: We obtained information on the maternal genotype from stored blood samples of 654 women who received supplementation with 400 mg DHA/d or a placebo from weeks 18 to 22 of gestation through delivery as part of a randomized controlled trial conducted in Cuernavaca, Mexico. We selected 4 tag SNPs (rs174455, rs174556, rs174602, and rs498793) in the FADS region for analysis. We used an ANOVA to test for the heterogeneity of the effect on birth weight across each of the 4 SNPs. Results: The mean ± SD birth weight was 3210 ± 470 g, and the weight-for-age z score (WAZ) was −0.24 ± 1.00. There were no intention-to-treat differences in birth weights. We showed significant heterogeneity by SNP rs174602 (P = 0.02); offspring of carriers of alleles TT and TC in the intervention group were heavier than those in the placebo group (WAZ: −0.13 ± 0.14 and −0.20 ± 0.08 compared with −0.55 ± 0.15 and −0.39 ± 0.09, respectively); there were no significant differences in offspring of rs174602 CC homozygotes (WAZ: −0.26 ± 0.09 in the intervention group compared with −0.04 ± 0.09 in the placebo group). We showed no significant heterogeneity across the other 3 FADS SNPs. Conclusion: Differential responses to prenatal DHA supplementation on the basis of the genetic makeup of target populations could explain the mixed evidence of the impact of DHA supplementation on birth weight. This

  3. A Mechanistic Pharmacokinetic Model for Liver Transporter Substrates Under Liver Cirrhosis Conditions

    PubMed Central

    Li, R; Barton, HA; Maurer, TS

    2015-01-01

    Liver cirrhosis is a disease characterized by the loss of functional liver mass. Physiologically based pharmacokinetic (PBPK) modeling was applied to interpret and predict how the interplay among physiological changes in cirrhosis affects pharmacokinetics. However, previous PBPK models under cirrhotic conditions were developed for permeable cytochrome P450 substrates and do not directly apply to substrates of liver transporters. This study characterizes a PBPK model for liver transporter substrates in relation to the severity of liver cirrhosis. A published PBPK model structure for liver transporter substrates under healthy conditions and the physiological changes for cirrhosis are combined to simulate pharmacokinetics of liver transporter substrates in patients with mild and moderate cirrhosis. The simulated pharmacokinetics under liver cirrhosis reasonably approximate observations. This analysis includes meta-analysis to obtain system-dependent parameters in cirrhosis patients and a top-down approach to improve understanding of the effect of cirrhosis on transporter-mediated drug disposition under cirrhotic conditions. PMID:26225262

  4. Identification of the Binding Region of the [2Fe-2S] Ferredoxin in Stearoyl-Acyl Carrier Protein Desaturase

    PubMed Central

    Sobrado, Pablo; Lyle, Karen S.; Kaul, Steven P.; Turco, Michelle M.; Arabshahi, Ida; Marwah, Ashok; Fox, Brian G.

    2008-01-01

    Stearoyl-acyl carrier protein desaturase (Δ9D) catalyzes the O2 and 2e- dependent desaturation of stearoyl-acyl carrier protein (18:0-ACP) to yield oleoyl-ACP (18:1-ACP). The 2e- are provided by essential interactions with reduced plant-type [2Fe-2S] ferredoxin (Fd). We have investigated the protein-protein interface involved in the Fd-Δ9D complex by use of chemical cross-linking, site-directed mutagenesis, steady-state kinetic approaches and molecular docking studies. Treatment of the different proteins with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide revealed that carboxylate residues from Fd and lysine residues from Δ9D contribute to the cross-linking. The single substitutions of K60A, K56A, and K230A on Δ9D decreased the kcat/KM for Fd by 4-, 22- and 2,400-fold, respectively, as compared to wt Δ9D and a K41A substitution. The double substitution K56A/K60A decreased the kcat/KM for Fd by 250-fold, while the triple mutation K56A/K60A/K230A decreased the kcat/KM for Fd by at least 700,000-fold. These results strongly implicate the triad of K56, K60 and K230 of Δ9D in the formation of a catalytic complex with Fd. Molecular docking studies indicate that electrostatic interactions between K56 and K60 and carboxylate groups on Fd may situate the [2Fe-2S] cluster of Fd near to W62, a surface residue that is structurally conserved in both ribonucleotide reductase and mycobacterial putative acyl-ACP desaturase DesA2. Owing to the considerably larger effects on catalysis, K230 appears to have other contributions to catalysis arising from its positioning in helix-7 and its close spatial location to the diiron center ligands E229 and H232. These results are considered in the light of the presently available models for Fd-mediated electron transfer in Δ9D and other protein-protein complexes. PMID:16605252

  5. Exposure to a Highly Caloric Palatable Diet during the Perinatal Period Affects the Expression of the Endogenous Cannabinoid System in the Brain, Liver and Adipose Tissue of Adult Rat Offspring

    PubMed Central

    Ramírez-López, María Teresa; Arco, Raquel; Decara, Juan; Vázquez, Mariam; Noemí Blanco, Rosario; Alén, Francisco; Suárez, Juan; Gómez de Heras, Raquel

    2016-01-01

    Recent studies have linked gestational exposure to highly caloric diets with a disrupted endogenous cannabinoid system (ECS). In the present study, we have extended these studies by analyzing the impact of the exposure to a palatable diet during gestation and lactation on a) the adult expression of endocannabinoid-related behaviors, b) the metabolic profile of adult offspring and c) the mRNA expression of the signaling machinery of the ECS in the hypothalamus, the liver and the adipose tissue of adult offspring of both sexes. Exposure to a palatable diet resulted in a) sex-dimorphic and perinatal diet specific feeding behaviors, including the differential response to the inhibitory effects of the cannabinoid receptor inverse agonist AM251, b) features of metabolic syndrome including increased adiposity, hyperleptinemia, hypertriglyceridemia and hypercholesterolemia and c) tissue and sex-specific changes in the expression of both CB1 and CB2 receptors and in that of the endocannabinoid-degrading enzymes FAAH and MAGL, being the adipose tissue the most affected organ analyzed. Since the effects were observed in adult animals that were weaned while consuming a normal diet, the present results indicate that the ECS is one of the targets of maternal programming of the offspring energy expenditure. These results clearly indicate that the maternal diet has long-term effects on the development of pups through multiple alterations of signaling homeostatic pathways that include the ECS. The potential relevance of these alterations for the current obesity epidemic is discussed. PMID:27806128

  6. [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.

  7. Effects of treatment with sucrose in drinking water on liver histology, lipogenesis and lipogenic gene expression in rats fed high-fiber diet.

    PubMed

    Mašek, Tomislav; Filipović, Natalija; Vuica, Ana; Starčević, Kristina

    2017-01-01

    We studied the influence of sucrose in drinking water on liver histology, fatty acid profile and lipogenic genes expression in rats maintained on high-fiber. The experimental groups were: control group (water) and sucrose group (sucrose solution in drinking water, 30% w/v). Liver histology of sucrose treated rats revealed steatosis and increased number of αSMA immunoreactive cells without the signs of fibrosis. Sucrose treatment increased de novo lipogenesis, lipid peroxidation and MUFA content and decreased PUFA content, C18:2n6 and C20:4n6 content in total phospholipids and phosphatidylethanolamine and C18:2n6 content in cardiolipin. RT-qPCR revealed increase in Δ-9-desaturase and SREBP1c gene expression and decrease in the Δ-5-desaturase and elongase 5 expression. Treatment with sucrose extensively changes fatty acid composition of hepatic lipid and phospholipid classes including cardiolipin, increases oxidative stress and causes pathological changes in liver in rats maintained on high-fiber diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Liver X receptor alpha regulates fatty acid synthase expression in chicken.

    PubMed

    Demeure, O; Duby, C; Desert, C; Assaf, S; Hazard, D; Guillou, H; Lagarrigue, S

    2009-12-01

    Liver X receptor alpha (LXRalpha), also referred to as nuclear receptor subfamily 1, group H, member 3 is a member of the nuclear hormone receptor superfamily, and has recently been shown to act as a master transcription factor governing hepatic lipogenesis in mammals. Liver X receptor alpha directly regulates both the expression of other lipogenic transcription factors and the expression of lipogenic enzymes, thereby enhancing hepatic fatty acid synthesis (FASN). In birds, like in humans, fatty acid synthesis primarily occurs in the liver. Whether LXRalpha is involved in hepatic regulation of lipogenic genes remained to be investigated in this species. Here we show that fatty acid synthase and the expression of other lipogenic genes (sterol regulatory element binding protein 1 and steroyl coenzyme A desaturase 1) are induced in chicken hepatoma cells in response to a pharmacological liver X receptor agonist, T0901317. A detailed analysis of the chicken FASN promoter revealed a functional liver X response element. These data define the chicken FASN gene as a direct target of LXRalpha and further expand the role of LXRalpha as a regulator of lipid metabolism in this species.

  9. The role of endoplasmic reticulum stress and insulin resistance in the occurrence of goose fatty liver.

    PubMed

    Geng, Tuoyu; Xia, Lili; Li, Fuyuan; Xia, Jing; Zhang, Yihui; Wang, Qianqian; Yang, Biao; Montgomery, Sean; Cui, Hengmi; Gong, Daoqing

    2015-09-11

    In mammals, insulin resistance (IR) is required for the occurrence of non-alcoholic fatty liver disease, and endoplasmic reticulum stress (ERS) contributes to IR. As geese have physiological and metabolic characteristics different from mammals, it is unclear whether these mechanisms also underlie the occurrence of goose fatty liver. To address this, 70-day-old geese were treated with an ERS inducer or overfed, and variables associated with ERS or IR were subsequently determined. The data indicated that the group of geese treated with the ERS inducer for 20d appeared to be more intolerant to blood glucose than the control group, and their livers showed features of hepatic steatosis, suggesting ERS can induce IR and hepatic steatosis in geese. In contrast, overfeeding did not induce ERS, probably due to the upregulated expression of fatty acid desaturases, but induced higher fasting/postprandial blood glucose as well as glucose intolerance in geese, which was accompanied by a dramatic increase of liver weight. Taken together, these findings delineated the role of ERS and IR in the occurrence of goose fatty liver. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Segmentation of liver region with tumorous tissues

    NASA Astrophysics Data System (ADS)

    Zhang, Xuejun; Lee, Gobert; Tajima, Tetsuji; Kitagawa, Teruhiko; Kanematsu, Masayuki; Zhou, Xiangrong; Hara, Takeshi; Fujita, Hiroshi; Yokoyama, Ryujiro; Kondo, Hiroshi; Hoshi, Hiroaki; Nawano, Shigeru; Shinozaki, Kenji

    2007-03-01

    Segmentation of an abnormal liver region based on CT or MR images is a crucial step in surgical planning. However, precisely carrying out this step remains a challenge due to either connectivities of the liver to other organs or the shape, internal texture, and homogeneity of liver that maybe extensively affected in case of liver diseases. Here, we propose a non-density based method for extracting the liver region containing tumor tissues by edge detection processing. False extracted regions are eliminated by a shape analysis method and thresholding processing. If the multi-phased images are available then the overall outcome of segmentation can be improved by subtracting two phase images, and the connectivities can be further eliminated by referring to the intensity on another phase image. Within an edge liver map, tumor candidates are identified by their different gray values relative to the liver. After elimination of the small and nonspherical over-extracted regions, the final liver region integrates the tumor region with the liver tissue. In our experiment, 40 cases of MDCT images were used and the result showed that our fully automatic method for the segmentation of liver region is effective and robust despite the presence of hepatic tumors within the liver.

  11. Quantification of liver fat: A comprehensive review.

    PubMed

    Goceri, Evgin; Shah, Zarine K; Layman, Rick; Jiang, Xia; Gurcan, Metin N

    2016-04-01

    Fat accumulation in the liver causes metabolic diseases such as obesity, hypertension, diabetes or dyslipidemia by affecting insulin resistance, and increasing the risk of cardiac complications and cardiovascular disease mortality. Fatty liver diseases are often reversible in their early stage; therefore, there is a recognized need to detect their presence and to assess its severity to recognize fat-related functional abnormalities in the liver. This is crucial in evaluating living liver donors prior to transplantation because fat content in the liver can change liver regeneration in the recipient and donor. There are several methods to diagnose fatty liver, measure the amount of fat, and to classify and stage liver diseases (e.g. hepatic steatosis, steatohepatitis, fibrosis and cirrhosis): biopsy (the gold-standard procedure), clinical (medical physics based) and image analysis (semi or fully automated approaches). Liver biopsy has many drawbacks: it is invasive, inappropriate for monitoring (i.e., repeated evaluation), and assessment of steatosis is somewhat subjective. Qualitative biomarkers are mostly insufficient for accurate detection since fat has to be quantified by a varying threshold to measure disease severity. Therefore, a quantitative biomarker is required for detection of steatosis, accurate measurement of severity of diseases, clinical decision-making, prognosis and longitudinal monitoring of therapy. This study presents a comprehensive review of both clinical and automated image analysis based approaches to quantify liver fat and evaluate fatty liver diseases from different medical imaging modalities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Stearoyl CoA Desaturase (SCD) Facilitates Proliferation of Prostate Cancer Cells through Enhancement of Androgen Receptor Transactivation

    PubMed Central

    Kim, Seung-Jin; Choi, Hojung; Park, Sung-Soo; Chang, Chawnshang; Kim, Eungseok

    2011-01-01

    Stearoyl-CoA desaturase (SCD), the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids, is highly expressed in prostate cancer although the SCD protein has been known to be rapidly turned over by proteolytic cleavage. The present data demonstrate that SCD can promote proliferation of androgen receptor (AR)-positive LNCaP prostate cancer cells and enhance dihydrotestosterone (DHT)-induced AR transcriptional activity, resulting in increased expression of prostatespecific antigen (PSA) and kallikrein-related peptidase 2 (KLK2). Interestingly, among the previously reported SCDderived peptides produced by proteolytic cleavage of SCD, a peptide spanning amino acids 130-162 of SCD (SCDCoRNR) contained the CoRNR box motif (LFLII) and enhanced AR transcriptional activity. In contrast, a mutant SCD-CoRNR in which Leu136 was replaced by Ala had no effect on AR transcriptional activity. Moreover, SCDCoRNR directly interacted with AR and inhibited RIP140 suppression of AR transactivation. Knockdown of the SCD gene by SCD microRNA suppressed AR transactivation with decreased cell proliferation, suggesting that SCD may regulate the proliferation of LNCaP cells via modulation of AR transcriptional activity. Moreover, ectopic expression of SCD in LNCaP cells facilitated LNCaP tumor formation and growth in nude mice. Together, the data indicate that SCD plays a key role in the regulation of AR transcriptional activity in prostate cancer cells. PMID:21331774

  13. ω-3 Long-Chain Polyunsaturated Fatty Acids and Fatty Acid Desaturase Activity Ratios as Eventual Endophenotypes for ADHD.

    PubMed

    Henríquez-Henríquez, Marcela; Solari, Sandra; Várgas, Gisela; Vásquez, Luis; Allende, Fidel; Castañón S, Carla; Tenorio, Marcela; Quiroga Gutiérrez, Teresa

    2015-11-01

    Epidemiological studies suggest that long-chain polyunsaturated fatty acids (LC-PUFAs) may be suitable as endophenotypes for ADHD. To be appropriated vulnerability traits, endophenotypes should be altered in unaffected relatives of index cases. Serum profiles of LC-PUFAs in unaffected relatives of ADHD patients remain understudied. The main objective of this study was to compare serum LC-PUFAs in ADHD patients, unaffected relatives of index cases, and general-population unaffected participants. LC-PUFA profiles of 72 participants (27 ADHD patients, 27 unaffected relatives, and 18 general-population participants) were obtained by gas chromatography-mass spectrometry (GC-MS). Groups were compared by parametrical statistics. Unaffected females from the general population presented lower Docosapentaenoic acid (DPA; p = .0012) and a-linolenic acid (ALA; p = .0091) levels compared with ADHD females and unaffected relatives. In addition, docosahexaenoic acid (DHA)/ALA and DHA/DPA ratios, addressing desaturase activity, were significantly lower in ADHD patients and unaffected relatives of ADHD patients in the female-subgroup (p = .022 and .04, respectively). DHA/ALA, DHA/DPA, serum DPA, and serum ALA may be suitable as endophenotypes for ADHD women. © The Author(s) 2012.

  14. Stearoyl-CoA desaturase activity in bovine cumulus cells protects the oocyte against saturated fatty acid stress

    PubMed Central

    Aardema, Hilde; van Tol, Helena T. A.; Wubbolts, Richard W.; Brouwers, Jos F. H. M.; Gadella, Bart M.; Roelen, Bernard A. J.

    2017-01-01

    Abstract Metabolic rich and poor conditions are both characterized by elevated free fatty acid levels and have been associated with impaired female fertility. In particular, saturated free fatty acids have a dose-dependent negative impact on oocyte developmental competence, while monounsaturated free fatty acids appear less harmful. Cumulus cells seem to protect the oocyte against free fatty acids, and the aim of this study was to determine the mechanism behind this protection In particular, the role of the enzyme stearoyl-CoA desaturase (SCD) that converts saturated into monounsaturated fatty acids was investigated. SCD gene and protein were abundantly expressed in cumulus cells, but expression was low in oocytes. The level of SCD protein expression in cumulus cells did not change when COCs were exposed to saturated stearic acid during maturation. SCD inhibition in the presence of stearic acid significantly reduced the developmental competence of oocytes and increased the incidence of apoptosis in cumulus cells. The esterified oleic/stearic acid ratio of the neutral lipid fraction in cumulus cells decreased in the presence of SCD inhibitors when COCs were exposed to saturated free fatty acids during maturation, indicating the SCD-specific conversion of saturated fatty acids under noninhibiting conditions. The observation that cumulus cells can desaturate the potentially toxic stearic acid into oleic acid via SCD activity provides a mechanistic insight into how the cumulus cells protect the oocyte against toxicity by saturated fatty acid. PMID:28486699

  15. Elevated stearoyl-CoA desaturase-1 expression in skeletal muscle contributes to abnormal fatty acid partitioning in obese humans

    PubMed Central

    Hulver, Matthew W.; Berggren, Jason R.; Carper, Michael J.; Miyazaki, Makoto; Ntambi, James M.; Hoffman, Eric P.; Thyfault, John P.; Stevens, Robert; Dohm, G. Lynis; Houmard, Joseph A.; Muoio, Deborah M.

    2014-01-01

    Summary Obesity and type 2 diabetes are strongly associated with abnormal lipid metabolism and accumulation of intramyocellular triacylglycerol, but the underlying cause of these perturbations are yet unknown. Herein, we show that the lipogenic gene, stearoyl-CoA desaturase 1 (SCD1), is robustly up-regulated in skeletal muscle from extremely obese humans. High expression and activity of SCD1, an enzyme that catalyzes the synthesis of monounsaturated fatty acids, corresponded with low rates of fatty acid oxidation, increased triacylglycerol synthesis and increased monounsaturation of muscle lipids. Elevated SCD1 expression and abnormal lipid partitioning were retained in primary skeletal myocytes derived from obese compared to lean donors, implying that these traits might be driven by epigenetic and/or heritable mechanisms. Overexpression of human SCD1 in myotubes from lean subjects was sufficient to mimic the obese phenotype. These results suggest that elevated expression of SCD1 in skeletal muscle contributes to abnormal lipid metabolism and progression of obesity. PMID:16213227

  16. Combined therapy of dietary fish oil and stearoyl-CoA desaturase 1 inhibition prevents the metabolic syndrome and atherosclerosis.

    PubMed

    Brown, J Mark; Chung, Soonkyu; Sawyer, Janet K; Degirolamo, Chiara; Alger, Heather M; Nguyen, Tam M; Zhu, Xuewei; Duong, My-Ngan; Brown, Amanda L; Lord, Caleb; Shah, Ramesh; Davis, Matthew A; Kelley, Kathryn; Wilson, Martha D; Madenspacher, Jennifer; Fessler, Michael B; Parks, John S; Rudel, Lawrence L

    2010-01-01

    Stearoyl-CoA desaturase 1 (SCD1) is a critical regulator of energy metabolism and inflammation. We have previously reported that inhibition of SCD1 in hyperlipidemic mice fed a saturated fatty acid (SFA)-enriched diet prevented development of the metabolic syndrome, yet surprisingly promoted severe atherosclerosis. In this study we tested whether dietary fish oil supplementation could prevent the accelerated atherosclerosis caused by SCD1 inhibition. LDLr(-/-), ApoB(100/100) mice were fed diets enriched in saturated fat or fish oil in conjunction with antisense oligonucleotide (ASO) treatment to inhibit SCD1. As previously reported, in SFA-fed mice, SCD1 inhibition dramatically protected against development of the metabolic syndrome, yet promoted atherosclerosis. In contrast, in mice fed fish oil, SCD1 inhibition did not result in augmented macrophage inflammatory response or severe atherosclerosis. In fact, the combined therapy of dietary fish oil and SCD1 ASO treatment effectively prevented both the metabolic syndrome and atherosclerosis. SCD1 ASO treatment in conjunction with dietary fish oil supplementation is an effective combination therapy to comprehensively combat the metabolic syndrome and atherosclerosis in mice.

  17. A novel selection signature in stearoyl-coenzyme A desaturase (SCD) gene for enhanced milk fat content in Bubalus bubalis.

    PubMed

    Maryam, J; Babar, M E; Bao, Zhang; Nadeem, A

    2016-10-01

    Modern molecular interventions are dynamic gears for breeding animals with superior genetic make-up. These scientific efforts lead us toward sustainable dairy herds with improved milk production in terms of yield and quality. Many of candidate genes have been dissected at molecular level, and suitable genetic markers have been identified in cattle, but this work has not been validated in buffaloes so far. Stearoyl-coenzyme A desaturase (SCD) has been a potential candidate gene for fat content of milk. Genomic analysis of SCD revealed a total of six variations that were identified through DNA sequencing of animals with lower and higher butter fat %age. After statistical analysis, genotype AB of p.K158I could be associated (P value <0.0001) with higher milk fat %age (10.5 ± 0.5464). This SNP was validated on larger data set by cleaved amplified polymorphic sequences (CAPS) by using DdeI. To scrutinize the functional consequences of p.K158I, 3D protein structure of SCD was predicted by homology modeling and this variation was found located in the vicinity of functional domain and a part of transmembrane helix of this membrane integrated protein. This is a first report toward genetic screening of SCD gene at molecular level in buffalo. This report illustrates the implication of SCD gene and in particular p.K158I variation, in imparting its effect on milk fat %age, which can be targeted in selection of superior dairy buffaloes.

  18. An increase in liver PPARγ2 is an initial event to induce fatty liver in response to a diet high in butter: PPARγ2 knockdown improves fatty liver induced by high-saturated fat.

    PubMed

    Yamazaki, Tomomi; Shiraishi, Sayaka; Kishimoto, Kyoko; Miura, Shinji; Ezaki, Osamu

    2011-06-01

    The effects of a diet rich in saturated fat on fatty liver formation and the related mechanisms that induce fatty liver were examined. C57BL/6J mice were fed butter or safflower oil as a high-fat (HF) diet (40% fat calories) for 2, 4, 10, or 17 weeks. Although both HF diets induced similar levels of obesity, HF butter-fed mice showed a two to threefold increase in liver triacylglycerol (TG) concentration compared to HF safflower oil-fed mice at 4 or 10 weeks without hyperinsulinemia. At 4 weeks, increases in peroxisome proliferator-activated receptor γ2 (PPARγ2), CD36, and adipose differentiation-related protein (ADRP) mRNAs were observed in HF butter-fed mice; at 10 weeks, an increase in sterol regulatory element-binding protein-1c (SREBP-1c) was observed; at 17 weeks, these increases were attenuated. At 4 weeks, a single injection of adenoviral vector-based short hairpin interfering RNA against PPARγ2 in HF butter-fed mice reduced PPARγ protein and mRNA of its target genes (CD36 and ADRP) by 43%, 43%, and 39%, respectively, with a reduction in liver TG concentration by 38% in 5 days. PPARγ2 knockdown also reduced mRNAs in lipogenic genes (fatty-acid-synthase, stearoyl-CoA desaturase 1, acetyl-CoA carboxylase 1) without alteration of SREBP-1c mRNA. PPARγ2 knockdown reduced mRNAs in genes related to inflammation (CD68, interleukin-1β, tumor necrosis factor-α, and monocyte chemoattractant protein-1). In conclusion, saturated fatty acid-rich oil induced fatty liver in mice, and this was triggered initially by an increase in PPARγ2 protein in the liver, which led to increased expression of lipogenic genes. Inactivation of PPARγ2 may improve fatty liver induced by HF saturated fat. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Liver transplant for cholestatic liver diseases.

    PubMed

    Carrion, Andres F; Bhamidimarri, Kalyan Ram

    2013-05-01

    Cholestatic liver diseases include a group of diverse disorders with different epidemiology, pathophysiology, clinical course, and prognosis. Despite significant advances in the clinical care of patients with cholestatic liver diseases, liver transplant (LT) remains the only definitive therapy for end-stage liver disease, regardless of the underlying cause. As per the United Network for Organ Sharing database, the rate of cadaveric LT for cholestatic liver disease was 18% in 1991, 10% in 2000, and 7.8% in 2008. This review summarizes the available evidence on various common and rare cholestatic liver diseases, disease-specific issues, and pertinent aspects of LT. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Autoimmune paediatric liver disease

    PubMed Central

    Mieli-Vergani, Giorgina; Vergani, Diego

    2008-01-01

    Liver disorders with a likely autoimmune pathogenesis in childhood include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is divided into two subtypes according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1 positive patients tend to present more acutely, at a younger age, and commonly have partial IgA deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment, and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological, and histological presentation of ASC is often indistinguishable from that of AIH type 1. In both, there are high IgG, non-organ specific autoantibodies, and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalization of biochemical parameters, and decreased inflammatory activity on follow up liver biopsies. However, the cholangiopathy can progress. There may be evolution from AIH to ASC over the years, despite treatment. De novo AIH after liver transplantation affects patients not transplanted for autoimmune disorders and is strikingly reminiscent of classical AIH, including elevated titres of serum antibodies, hypergammaglobulinaemia, and histological findings of interface hepatitis, bridging fibrosis, and collapse. Like classical AIH, it responds to treatment with prednisolone and azathioprine. De novo AIH post liver transplantation may derive from interference by calcineurin inhibitors with the intrathymic physiological mechanisms of T-cell maturation and selection. Whether this condition is a

  1. Autoimmune paediatric liver disease.

    PubMed

    Mieli-Vergani, Giorgina; Vergani, Diego

    2008-06-07

    Liver disorders with a likely autoimmune pathogenesis in childhood include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is divided into two subtypes according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1 positive patients tend to present more acutely, at a younger age, and commonly have partial IgA deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment, and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological, and histological presentation of ASC is often indistinguishable from that of AIH type 1. In both, there are high IgG, non-organ specific autoantibodies, and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalization of biochemical parameters, and decreased inflammatory activity on follow up liver biopsies. However, the cholangiopathy can progress. There may be evolution from AIH to ASC over the years, despite treatment. De novo AIH after liver transplantation affects patients not transplanted for autoimmune disorders and is strikingly reminiscent of classical AIH, including elevated titres of serum antibodies, hypergammaglobulinaemia, and histological findings of interface hepatitis, bridging fibrosis, and collapse. Like classical AIH, it responds to treatment with prednisolone and azathioprine. De novo AIH post liver transplantation may derive from interference by calcineurin inhibitors with the intrathymic physiological mechanisms of T-cell maturation and selection. Whether this condition is a

  2. Supplementation with antioxidant-rich extra virgin olive oil prevents hepatic oxidative stress and reduction of desaturation capacity in mice fed a high-fat diet: Effects on fatty acid composition in liver and extrahepatic tissues.

    PubMed

    Rincón-Cervera, Miguel Angel; Valenzuela, Rodrigo; Hernandez-Rodas, María Catalina; Marambio, Macarena; Espinosa, Alejandra; Mayer, Susana; Romero, Nalda; Barrera M Sc, Cynthia; Valenzuela, Alfonso; Videla, Luis A

    2016-01-01

    The aim of this study was to assess the effect of dietary supplementation with extra virgin olive oil (EVOO) in mice on the reduction of desaturase and antioxidant enzymatic activities in liver, concomitantly with long-chain polyunsaturated fatty acids (LCPUFA) profiles in liver and extrahepatic tissues induced by a high-fat diet (HFD). Male mice C57 BL/6 J were fed with a control diet (CD; 10% fat, 20% protein, 70% carbohydrates) or an HFD (60% fat, 20% protein, 20% carbohydrates) for 12 wk. Animals were supplemented with 100 mg/d EVOO with different antioxidant contents (EVOO I, II, and III). After the intervention, blood and several tissues were analyzed. Dietary supplementation with EVOO with the highest antioxidant content and antioxidant capacity (EVOO III) significantly reduced fat accumulation in liver and the plasmatic metabolic alterations caused by HFD and produced a normalization of oxidative stress-related parameters, desaturase activities, and LCPUFA content in tissues. Data suggest that dietary supplementation with EVOO III may prevent oxidative stress and reduction of biosynthesis and accretion of ω-3 LCPUFA in the liver of HFD-fed mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Pyogenic liver abscess

    MedlinePlus

    Liver abscess; Bacterial liver abscess ... There are many possible causes of liver abscesses, including: Abdominal infection, such as appendicitis , diverticulitis , or a perforated bowel Infection in the blood Infection of the bile draining tubes ...

  4. Liver function tests

    MedlinePlus

    Liver function tests are common tests that are used to see how well the liver is working. Tests include: ... E, Bowne WB, Bluth MH. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry's Clinical ...

  5. Liver Function Tests

    MedlinePlus

    ... food, store energy, and remove poisons. Liver function tests are blood tests that check to see how well your liver ... hepatitis and cirrhosis. You may have liver function tests as part of a regular checkup. Or you ...

  6. Fatty Liver Disease

    MedlinePlus

    ... fatty liver disease that is not related to heavy alcohol use. There are two kinds: Simple fatty ... disease? Alcoholic fatty liver disease is due to heavy alcohol use. Your liver breaks down most of ...

  7. American Liver Foundation

    MedlinePlus

    ... Media Helpful Links Liver Cancer Information Available in Chinese Learn more about liver cancer HERE . Thanks to ... in Northern California, you can speak to a Chinese speaking agent with your liver cancer questions. Call ...

  8. Sexual dysfunction after liver transplantation.

    PubMed

    Burra, Patrizia

    2009-11-01

    1. The goal of liver transplantation is not only to ensure the survival of patients but also to offer patients the opportunity to achieve a good balance between the functional efficacy of the graft and their psychological and physical integrity. The quality of life after transplantation may be affected by unsatisfactory sexual activity and reproductive performance. 2. Sexual dysfunction and sex hormone disturbances are widely reported in men and women with chronic liver disease before liver transplantation. 3. Successful liver transplantation should lead to improvements in sexual function and sex hormone disturbances in both men and women, therefore improving reproductive performance, but immunosuppressive drugs may interfere with hormone metabolism. 4. Pregnancy is often successful after liver transplantation, despite the potentially toxic effects of immunosuppressive drug therapy, but fetal and maternal outcomes should be regularly assessed. 5. More detailed and comprehensive data are needed in the field of sexual function after transplantation, and new strategies are needed to support and inform patients on the waiting list and after liver transplantation. (c) 2009 AASLD.

  9. Genotype-specific responses in Atlantic salmon (Salmo salar) subject to dietary fish oil replacement by vegetable oil: a liver transcriptomic analysis.

    PubMed

    Morais, Sofia; Pratoomyot, Jarunan; Taggart, John B; Bron, James E; Guy, Derrick R; Bell, J Gordon; Tocher, Douglas R

    2011-05-20

    Expansion of aquaculture is seriously limited by reductions in fish oil (FO) supply for aquafeeds. Terrestrial alternatives such as vegetable oils (VO) have been investigated and recently a strategy combining genetic selection with changes in diet formulations has been proposed to meet growing demands for aquaculture products. This study investigates the influence of genotype on transcriptomic responses to sustainable feeds in Atlantic salmon. A microarray analysis was performed to investigate the liver transcriptome of two family groups selected according to their estimated breeding values (EBVs) for flesh lipid content, 'Lean' or 'Fat', fed diets containing either FO or a VO blend. Diet principally affected metabolism genes, mainly of lipid and carbohydrate, followed by immune response genes. Genotype had a much lower impact on metabolism-related genes and affected mostly signalling pathways. Replacement of dietary FO by VO caused an up-regulation of long-chain polyunsaturated fatty acid biosynthesis, but there was a clear genotype effect as fatty acyl elongase (elovl2) was only up-regulated and desaturases (Δ5 fad and Δ6 fad) showed a higher magnitude of response in Lean fish, which was reflected in liver fatty acid composition. Fatty acid synthase (FAS) was also up-regulated by VO and the effect was independent of genotype. Genetic background of the fish clearly affected regulation of lipid metabolism, as PPARα and PPARβ were down-regulated by the VO diet only in Lean fish, while in Fat salmon SREBP-1 expression was up-regulated by VO. In addition, all three genes had a lower expression in the Lean family group than in the Fat, when fed VO. Differences in muscle adiposity between family groups may have been caused by higher levels of hepatic fatty acid and glycerophospholipid synthesis in the Fat fish, as indicated by the expression of FAS, 1-acyl-sn-glycerol-3-phosphate acyltransferase and lipid phosphate phosphohydrolase 2. This study has identified

  10. Genotype-specific responses in Atlantic salmon (Salmo salar) subject to dietary fish oil replacement by vegetable oil: a liver transcriptomic analysis

    PubMed Central

    2011-01-01

    Background Expansion of aquaculture is seriously limited by reductions in fish oil (FO) supply for aquafeeds. Terrestrial alternatives such as vegetable oils (VO) have been investigated and recently a strategy combining genetic selection with changes in diet formulations has been proposed to meet growing demands for aquaculture products. This study investigates the influence of genotype on transcriptomic responses to sustainable feeds in Atlantic salmon. Results A microarray analysis was performed to investigate the liver transcriptome of two family groups selected according to their estimated breeding values (EBVs) for flesh lipid content, 'Lean' or 'Fat', fed diets containing either FO or a VO blend. Diet principally affected metabolism genes, mainly of lipid and carbohydrate, followed by immune response genes. Genotype had a much lower impact on metabolism-related genes and affected mostly signalling pathways. Replacement of dietary FO by VO caused an up-regulation of long-chain polyunsaturated fatty acid biosynthesis, but there was a clear genotype effect as fatty acyl elongase (elovl2) was only up-regulated and desaturases (Δ5 fad and Δ6 fad) showed a higher magnitude of response in Lean fish, which was reflected in liver fatty acid composition. Fatty acid synthase (FAS) was also up-regulated by VO and the effect was independent of genotype. Genetic background of the fish clearly affected regulation of lipid metabolism, as PPARα and PPARβ were down-regulated by the VO diet only in Lean fish, while in Fat salmon SREBP-1 expression was up-regulated by VO. In addition, all three genes had a lower expression in the Lean family group than in the Fat, when fed VO. Differences in muscle adiposity between family groups may have been caused by higher levels of hepatic fatty acid and glycerophospholipid synthesis in the Fat fish, as indicated by the expression of FAS, 1-acyl-sn-glycerol-3-phosphate acyltransferase and lipid phosphate phosphohydrolase 2. Conclusions

  11. Nonalcoholic Fatty Liver Disease

    MedlinePlus

    ... fatty liver, alcoholic steatohepatitis, ascites, choline deficiency, cirrhosis, drug-induced fatty liver, edema, encephalopathy, glycogen storage disorder, gynecomastia, hepatic steatosis, hepatomegaly, hereditary fructose intolerance, homocystinuria, hyperlipidemia, ...

  12. Treatment of rats with Jiangzhi Capsule improves liquid fructose-induced fatty liver: modulation of hepatic expression of SREBP-1c and DGAT-2.

    PubMed

    Zhao, Yuanyang; Pan, Yongquan; Yang, Yifan; Batey, Robert; Wang, Jianwei; Li, Yuhao

    2015-06-02

    Jiangzhi Capsule is an Australian listed patented traditional Chinese medicine and has been used for management of lipid abnormalities over the past 10 years. To obtain a better understanding regarding Jiangzhi Capsule, the present study investigated the effects and underlying mechanisms of Jiangzhi Capsule on chronic fructose overconsumption-induced lipid abnormalities. Male rats were treated with liquid fructose in their drinking water over 14 weeks. Jiangzhi Capsule was co-administered (once daily, by oral gavage) during the last 7 weeks. Indexes of lipid and glucose homeostasis were determined enzymatically, by ELISA and/or histologically. Gene expression was analyzed by real-time PCR, Western blot and/or immunohistochemistry. Treatment with Jiangzhi Capsule (100 mg/kg) attenuated fructose-induced excessive triglyceride accumulation and Oil Red O-stained area in the liver. This effect was accompanied by amelioration of hyperinsulinemia. There was no significant difference in intakes of fructose and chow, and body weight between fructose control and fructose Jiangzhi Capsule-treated groups. Mechanistically, Jiangzhi Capsule downregulated fructose-stimulated hepatic overexpression of sterol regulatory element binding protein (SREBP)-1/1c at the mRNA and protein levels. Accordingly, the SREBP-1c downstream genes, acetyl-CoA carboxylase-1 and stearoyl-CoA desaturase-1, were also inhibited. In addition, acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver was also inhibited after Jiangzhi Capsule treatment. In contrast, Jiangzhi Capsule affected neither carbohydrate response element binding protein, peroxisome proliferator-activated receptor (PPAR)-gamma and DGAT-1, nor PPAR-alpha and its target genes. These findings demonstrate the anti-steatotic action of Jiangzhi Capsule in fructose-fed rats, and modulation of hepatic SREBP-1c and DGAT-2 involved in hepatic de novo synthesis of fatty acids and triglyceride

  13. Assessment of liver size by ultrasonography.

    PubMed

    Patzak, Monika; Porzner, Marc; Oeztuerk, Suemeyra; Mason, Richard Andrew; Wilhelm, Manfred; Graeter, Tilmann; Kratzer, Wolfgang; Haenle, Mark Martin; Akinli, Atilla Serif

    2014-09-01

    To determine liver span sonographically in a randomly selected population sample and identify factors that affect liver size. A total of 1,789 subjects (963 females, 826 males; mean age 41.8 ± 12.8 years) underwent sonographic examination of the liver in the midclavicular line to determine liver span. Subjects underwent physical examination and blood tests and completed a standardized interview questionnaire. The average liver span in the midclavicular line for the overall collective was 15.0 ± 1.5 cm; the average for females was 14.9 ± 1.6 cm and 15.1 ± 1.5 cm for males. Liver span exceeded 16 cm in 24.3% of subjects. Results of the multivariate analysis showed that, of the factors potentially influencing liver span, gender, age, body mass index, body height, fatty liver (p < 0.0001), waist-to-hip ratio (p = 0.015), and metabolic syndrome (p = 0.032) are significant. By contrast, diabetes mellitus, alcohol consumption, tobacco consumption, physical activity, and laboratory findings showed no influence. Sonographic measurement of liver span in the midclavicular line is a simple method for routine clinical use. Gender, age, body mass index, waist-to-hip ratio, body height, hepatic steatosis, and metabolic syndrome are factors associated with liver span. © 2014 Wiley Periodicals, Inc.

  14. Alcoholic Liver Disease and Liver Transplantation.

    PubMed

    Gallegos-Orozco, Juan F; Charlton, Michael R

    2016-08-01

    Excessive alcohol use is a common health care problem worldwide and is associated with significant morbidity and mortality. Alcoholic liver disease represents the second most frequent indication for liver transplantation in North America and Europe. The pretransplant evaluation of patients with alcoholic liver disease should aim at identifying those at high risk for posttransplant relapse of alcohol use disorder, as return to excessive drinking can be deleterious to graft and patient survival. Carefully selected patients with alcoholic liver disease, including those with severe alcoholic hepatitis, will have similar short-term and long-term outcomes when compared with other indications for liver transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Imaging of the transplant liver.

    PubMed

    Babyn, Paul Sheppard

    2010-04-01

    As the number of patients with liver transplants continues to increase, radiologists need to be aware of the normal post-operative appearance of the different liver transplants currently performed along with the wide variety of complications encountered. The complications commonly affect the biliar and vascular systems and can include anastomotic bile leakage and biliary stenosis along with stenosis or obstruction of the hepatic artery, portal or hepatic veins and IVC. Other complications include parenchymal abnormalities such as hepatic infarction, organ rejection, localized collections and post transplant lymphoproliferative disorder. This article reviews and illustrates the role of imaging for pediatric transplantation including the role of interventional radiology.

  16. Rice mutants deficient in ω-3 fatty acid desaturase (FAD8) fail to acclimate to cold temperatures.

    PubMed

    Tovuu, Altanzaya; Zulfugarov, Ismayil S; Wu, Guangxi; Kang, In Soon; Kim, Choongrak; Moon, Byoung Yong; An, Gynheung; Lee, Choon-Hwan

    2016-12-01

    To investigate the role of ω-3 fatty acid (FA) desaturase (FAD8) during cold acclimation in higher plants, we characterized three independent T-DNA insertional knock-out mutants of OsFAD8 from rice (Oryza sativa L.). At room temperature (28 °C), osfad8 plants exhibited significant alterations in fatty acid (FA) unsaturation for all four investigated plastidic lipid classes. During a 5-d acclimation period at 4 °C, further changes in FA unsaturation in both wild-type (WT) and mutant plants varied according to the type of lipid. We also monitored the fluidity of the thylakoid membrane using a threshold temperature to represent the change in fluorescence. The values were altered significantly by both FAD8 mutation and cold acclimation, suggesting that factors other than FAD8 are involved in C18 FA unsaturation and fluctuations in membrane fluidity. Similarly, significant changes were noted for both the mutant and WT samples in terms of their FA compositions as well as activities related to photosystem (PS) I, PSII, and photoprotection. This included the development of non-photochemical quenching and increased zeaxanthin accumulation. Despite the relatively small changes in FA composition during cold acclimation, cold-inducible FAD8 knock-out mutants displayed strong differences in photoprotective activities and a further drop in membrane fluidity. The mutants were more sensitive than WT to short-term low-temperature stress that resulted in increased production of reactive oxygen species after 5 d of chilling. Taken together, our findings suggest that FA unsaturation by OsFAD8 is crucial for the acclimation of higher plants to low-temperature stress. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Diversity of Δ12 fatty acid desaturases in santalaceae and their role in production of seed oil acetylenic fatty acids.

    PubMed

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

    2013-11-08

    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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. Identification and evaluation of ω-3 fatty acid desaturase genes for hyperfortifying α-linolenic acid in transgenic rice seed.

    PubMed

    Liu, Hua Liang; Yin, Zhi Jie; Xiao, Li; Xu, Yi Nong; Qu, Le Qing

    2012-05-01

    α-Linolenic acid (ALA) deficiency and a skewed of ω6:ω3 fatty acid ratio in the diet are a major explanation for the prevalence of cardiovascular diseases and inflammatory/autoimmune diseases. There is a need to enhance the ALA content and to reduce the ratio of linoleic acid (LA) to ALA. Six ω-3 (Δ-15) fatty acid desaturase (FAD) genes were cloned from rice and soybean. The subcellular localizations of the proteins were identified. The FAD genes were introduced into rice under the control of an endosperm-specific promoter, GluC, or a Ubi-1 promoter to evaluate their potential in increasing the ALA content in seeds. The ALA contents in the seeds of endoplasmic reticulum (ER)-localized GmFAD3-1 and OsFAD3 overexpression lines increased from 0.36 mg g⁻¹ to 8.57 mg g⁻¹ and 10.06 mg g⁻¹, respectively, which was 23.8- and 27.9-fold higher than that of non-transformants. The trait of high ALA content was stably inheritable over three generations. Homologous OsFAD3 is more active than GmFAD3-1 in catalysing LA conversion to ALA in rice seeds. Overexpression of ER-localized GmFAD3-2/3 and chloroplast-localized OsFAD7/8 had less effect on increasing the ALA content in rice seeds. The GluC promoter is advantageous compared with Ubi-1 in this experimental system. The enhanced ALA was preferentially located at the sn-2 position in triacylglycerols. A meal-size portion of high ALA rice would meet >80% of the daily adult ALA requirement. The ALA-rich rice could be expected to ameliorate much of the global dietary ALA deficiency.

  3. Genome-Wide Survey and Characterization of Fatty Acid Desaturase Gene Family in Brassica napus and Its Parental Species.

    PubMed

    Xue, Yufei; Chen, Baojun; Wang, Rui; Win, Aung Naing; Li, Jiana; Chai, Yourong

    2018-02-01

    Rapeseed (Brassica napus) is an important oilseed crop worldwide, and fatty acid (FA) compositions determine the nutritional and economic value of its seed oil. Fatty acid desaturases (FADs) play a pivotal role in regulating FA compositions, but to date, no comprehensive genome-wide analysis of FAD gene family in rapeseed and its parent species has been reported. In this study, using homology searches, 84, 45, and 44 FAD genes were identified in rapeseed, Brassica rapa, and Brassica oleracea genomes, respectively. These FAD genes were unevenly located in 17 chromosomes and 2 scaffolds of rapeseed, 9 chromosomes and 1 scaffold of B. rapa, and all the chromosomes of B. oleracea. Phylogenetic analysis showed that the soluble and membrane-bound FADs in the three Brassica species were divided into four and six subfamilies, respectively. Generally, the soluble FADs contained two conserved histidine boxes, while three highly conserved histidine boxes were harbored in membrane-bound FADs. Exon-intron structure, intron phase, and motif composition and position were highly conserved in each FAD subfamily. Putative subcellular locations of FAD proteins in three Brassica species were consistent with those of corresponding known FADs. In total, 25 of simple sequence repeat (SSR) loci were found in FAD genes of the three Brassica species. Transcripts of selected FAD genes in the three species were examined in various organs/tissues or stress treatments from NCBI expressed sequence tag (EST) database. This study provides a critical molecular basis for quality improvement of rapeseed oil and facilitates our understanding of key roles of FAD genes in plant growth and development and stress response.

  4. Stearoyl-Acyl Carrier Protein Desaturase Mutations Uncover an Impact of Stearic Acid in Leaf and Nodule Structure.

    PubMed

    Lakhssassi, Naoufal; Colantonio, Vincent; Flowers, Nicholas D; Zhou, Zhou; Henry, Jason; Liu, Shiming; Meksem, Khalid

    2017-07-01

    Stearoyl-acyl carrier protein desaturase (SACPD-C) has been reported to control the accumulation of seed stearic acid; however, no study has previously reported its involvement in leaf stearic acid content and impact on leaf structure and morphology. A subset of an ethyl methanesulfonate mutagenized population of soybean ( Glycine max ) 'Forrest' was screened to identify mutants within the GmSACPD-C gene. Using a forward genetics approach, one nonsense and four missense Gmsacpd-c mutants were identified to have high levels of seed, nodule, and leaf stearic acid content. Homology modeling and in silico analysis of the GmSACPD-C enzyme revealed that most of these mutations were localized near or at conserved residues essential for diiron ion coordination. Soybeans carrying Gmsacpd-c mutations at conserved residues showed the highest stearic acid content, and these mutations were found to have deleterious effects on nodule development and function. Interestingly, mutations at nonconserved residues show an increase in stearic acid content yet retain healthy nodules. Thus, random mutagenesis and mutational analysis allows for the achievement of high seed stearic acid content with no associated negative agronomic characteristics. Additionally, expression analysis demonstrates that nodule leghemoglobin transcripts were significantly more abundant in soybeans with deleterious mutations at conserved residues of GmSACPD-C. Finally, we report that Gmsacpd-c mutations cause an increase in leaf stearic acid content and an alteration of leaf structure and morphology in addition to differences in nitrogen-fixing nodule structure. © 2017 American Society of Plant Biologists. All Rights Reserved.

  5. Role of liver progenitors in liver regeneration

    PubMed Central

    Best, Jan; Manka, Paul; Syn, Wing-Kin; Dollé, Laurent; van Grunsven, Leo A.

    2015-01-01

    During massive liver injury and hepatocyte loss, the intrinsic regenerative capacity of the liver by replication of resident hepatocytes is overwhelmed. Treatment of this condition depends on the cause of liver injury, though in many cases liver transplantation (LT) remains the only curative option. LT for end stage chronic and acute liver diseases is hampered by shortage of donor organs and requires immunosuppression. Hepatocyte transplantation is limited by yet unresolved technical difficulties. Since currently no treatment is available to facilitate liver regeneration directly, therapies involving the use of resident liver stem or progenitor cells (LPCs) or non-liver stem cells are coming to fore. LPCs are quiescent in the healthy liver, but may be activated under conditions where the regenerative capacity of mature hepatocytes is severely impaired. Non-liver stem cells include embryonic stem cells (ES cells) and mesenchymal stem cells (MSCs). In the first section, we aim to provide an overview of the role of putative cytokines, growth factors, mitogens and hormones in regulating LPC response and briefly discuss the prognostic value of the LPC response in clinical practice. In the latter section, we will highlight the role of other (non-liver) stem cells in transplantation and discuss advantages and disadvantages of ES cells, induced pluripotent stem cells (iPS), as well as MSCs. PMID:25713804

  6. Role of liver progenitors in liver regeneration.

    PubMed

    Best, Jan; Manka, Paul; Syn, Wing-Kin; Dollé, Laurent; van Grunsven, Leo A; Canbay, Ali

    2015-02-01

    During massive liver injury and hepatocyte loss, the intrinsic regenerative capacity of the liver by replication of resident hepatocytes is overwhelmed. Treatment of this condition depends on the cause of liver injury, though in many cases liver transplantation (LT) remains the only curative option. LT for end stage chronic and acute liver diseases is hampered by shortage of donor organs and requires immunosuppression. Hepatocyte transplantation is limited by yet unresolved technical difficulties. Since currently no treatment is available to facilitate liver regeneration directly, therapies involving the use of resident liver stem or progenitor cells (LPCs) or non-liver stem cells are coming to fore. LPCs are quiescent in the healthy liver, but may be activated under conditions where the regenerative capacity of mature hepatocytes is severely impaired. Non-liver stem cells include embryonic stem cells (ES cells) and mesenchymal stem cells (MSCs). In the first section, we aim to provide an overview of the role of putative cytokines, growth factors, mitogens and hormones in regulating LPC response and briefly discuss the prognostic value of the LPC response in clinical practice. In the latter section, we will highlight the role of other (non-liver) stem cells in transplantation and discuss advantages and disadvantages of ES cells, induced pluripotent stem cells (iPS), as well as MSCs.

  7. Liver xenotransplantation.

    PubMed

    Marino, I R; Tzakis, A G; Fung, J J; Todo, S; Doyle, H R; Manez, R; Starzl, T E

    1993-10-01

    During the past 30 years orthotopic liver transplantation has become a highly successful form of surgical treatments. The significant advances achieved in this field have led to an increased demand for organs and created a wide gap between organ availability and organ supply. A wider availability of organs for transplantation would allow an expansions rather than a contraction of the indications for transplantation, and, at the same time a relaxation of the patient selection criteria. All these facts clearly justify the renewed interest observed in the last decade in xenotransplantation. The original concept of xenografting, meaning the transplantation of cells, tissues, or organs between different species, is so ancient that it is easily recognizable in Greek and Roman mythology. The centaur Chiron, the teacher of Esculapius, and the Chimera are legendary examples of discordant xenogeneic creatures. However, it is only during this century that scientists have been able to bring this idea into the clinical arena. The early efforts were prompted by the shortage of humans organs at a time when there were few alternatives for treating end-stage organ failure.

  8. Tuberculosis and liver disease: management issues.

    PubMed

    Sonika, Ujjwal; Kar, Premashis

    2012-01-01

    Tuberculosis is one of the most common diseases in India and has attained epidemic proportions. Tuberculosis and liver are related in many ways. Liver disease can occur due to hepatic tuberculosis or the treatment with various anti-tubercular drugs may precipitate hepatic injury or patients with chronic liver disease may develop tuberculosis and pose special management problems. Tuberculosis per se can affect liver in three forms. The most common form is the diffuse hepatic involvement, seen along with pulmonary or miliary tuberculosis. The second is granulomatous hepatitis and the third, much rarer form presents as focal/local tuberculoma or abscess. Tubercular disease of liver occurring along with pulmonary involvement as in disseminated tuberculosis is treated with standard regimen for pulmonary tuberculosis. Granulomatous hepatitis and tubercular liver abscess are treated like any other extra-pulmonary tubercular lesions without any extra risk of hepatotoxicity by anti-tubercular drugs. Treatment of tuberculosis in patients who already have a chronic liver disease poses various clinical challenges. There is an increased risk of drug induced hepatitis in these patients and its implications are potentially more serious in these patients as their hepatic reserve is already depleted. However, hepatotoxic anti-tubercular drugs can be safely used in these patients if the number of drugs used is adjusted appropriately. Thus, the main principle is to closely monitor the patient for signs of worsening liver disease and to reduce the number of hepatotoxic drugs in the anti-tubercular regimen according to the severity of underlying liver disease.

  9. Liver fibrosis markers in alcoholic liver disease.

    PubMed

    Chrostek, Lech; Panasiuk, Anatol

    2014-07-07

    Alcohol is one of the main factors of liver damage. The evaluation of the degree of liver fibrosis is of great value for therapeutic decision making in patients with alcoholic liver disease (ALD). Staging of liver fibrosis is essential to define prognosis and management of the disease. Liver biopsy is a gold standard as it has high sensitivity and specificity in fibrosis diagnostics. Taking into account the limitations of liver biopsy, there is an exigency to introduce non-invasive serum markers for fibrosis that would be able to replace liver biopsy. Ideal serum markers should be specific for the liver, easy to perform and independent to inflammation and fibrosis in other organs. Serum markers of hepatic fibrosis are divided into direct and indirect. Indirect markers reflect alterations in hepatic function, direct markers reflect extracellular matrix turnover. These markers should correlate with dynamic changes in fibrogenesis and fibrosis resolution. The assessment of the degree of liver fibrosis in alcoholic liver disease has diagnostic and prognostic implications, therefore noninvasive assessment of fibrosis remains important. There are only a few studies evaluating the diagnostic and prognostic values of noninvasive biomarkers of fibrosis in patients with ALD. Several noninvasive laboratory tests have been used to assess liver fibrosis in patients with alcoholic liver disease, including the hyaluronic acid, FibroTest, FibrometerA, Hepascore, Forns and APRI indexes, FIB4, an algorithm combining Prothrombin index (PI), α-2 macroglobulin and hyaluronic acid. Among these tests, Fibrotest, FibrometerA and Hepascore demonstrated excellent diagnostic accuracy in identifying advanced fibrosis and cirrhosis, and additionally, Fibrotest was independently associated with survival. Therefore, the use of biomarkers may reduce the need for liver biopsy and permit an earlier treatment of alcoholic patients.

  10. Western diet-induced hepatic steatosis and alterations in the liver transcriptome in adult Brown-Norway rats.

    PubMed

    Roberts, Michael D; Mobley, C Brooks; Toedebush, Ryan G; Heese, Alexander J; Zhu, Conan; Krieger, Anna E; Cruthirds, Clayton L; Lockwood, Christopher M; Hofheins, John C; Wiedmeyer, Charles E; Leidy, Heather J; Booth, Frank W; Rector, R Scott

    2015-10-30

    The purpose of this study was to investigate the effects of sub-chronic high fat, high sucrose diet (also termed 'Westernized diet' or WD) feeding on the liver transcriptome during early nonalcoholic fatty liver disease (NAFLD) development. Brown Norway male rats (9 months of age) were randomly assigned to receive ad libitum access to a control (CTL; 14 % kcal fat, 1.2 % sucrose by weight) diet or WD (42 % kcal from fat, 34 % sucrose by weight) for 6 weeks. Six weeks of WD feeding caused hepatic steatosis development as evidenced by the 2.25-fold increase in liver triacylglycerol content, but did not induce advanced liver disease (i.e., no overt inflammation or fibrosis) in adult Brown Norway rats. RNA deep sequencing (RNA-seq) revealed that 94 transcripts were altered in liver by WD feeding (46 up-, 48 down-regulated, FDR < 0.05). Specifically, the top differentially regulated gene network by WD feeding was 'Lipid metabolism, small molecular biochemistry, vitamin and mineral metabolism' (Ingenuity Pathway Analysis (IPA) score 61). The top-regulated canonical signaling pathway in WD-fed rats was the 'Superpathway of cholesterol biosynthesis' (10/29 genes regulated, p = 1.68E-17), which coincides with a tendency for serum cholesterol levels to increase in WD-fed rats (p = 0.09). Remarkably, liver stearoyl-CoA desaturase (Scd) mRNA expression was by far the most highly-induced transcript in WD-fed rats (approximately 30-fold, FDR = 0.01) which supports previous literature underscoring this gene as a crucial target during NAFLD development. In summary, sub-chronic WD feeding appears to increase hepatic steatosis development over a 6-week period but only induces select inflammation-related liver transcripts, mostly acute phase response genes. These findings continue to outline the early stages of NAFLD development prior to overt liver inflammation and advanced liver disease.

  11. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. On the Structure and Function of the Phytoene Desaturase CRTI from Pantoea ananatis, a Membrane-Peripheral and FAD-Dependent Oxidase/Isomerase

    PubMed Central

    Gemmecker, Sandra; Poussin-Courmontagne, Pierre; Mailliot, Justine; McEwen, Alastair G.; Ghisla, Sandro; Al-Babili, Salim; Cavarelli, Jean; Beyer, Peter

    2012-01-01

    CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC) liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C40 hydrocarbon substrate. PMID:22745782

  13. TALEN-mediated targeted mutagenesis of fatty acid desaturase 2 (FAD2) in peanut (Arachis hypogaea L.) promotes the accumulation of oleic acid.

    PubMed

    Wen, Shijie; Liu, Hao; Li, Xingyu; Chen, Xiaoping; Hong, Yanbin; Li, Haifen; Lu, Qing; Liang, Xuanqiang

    2018-05-01

    A first creation of high oleic acid peanut varieties by using transcription activator-like effecter nucleases (TALENs) mediated targeted mutagenesis of Fatty Acid Desaturase 2 (FAD2). Transcription activator like effector nucleases (TALENs), which allow the precise editing of DNA, have already been developed and applied for genome engineering in diverse organisms. However, they are scarcely used in higher plant study and crop improvement, especially in allopolyploid plants. In the present study, we aimed to create targeted mutagenesis by TALENs in peanut. Targeted mutations in the conserved coding sequence of Arachis hypogaea fatty acid desaturase 2 (AhFAD2) were created by TALENs. Genetic stability of AhFAD2 mutations was identified by DNA sequencing in up to 9.52 and 4.11% of the regeneration plants at two different targeted sites, respectively. Mutation frequencies among AhFAD2 mutant lines were significantly correlated to oleic acid accumulation. Genetically, stable individuals of positive mutant lines displayed a 0.5-2 fold increase in the oleic acid content compared with non-transgenic controls. This finding suggested that TALEN-mediated targeted mutagenesis could increase the oleic acid content in edible peanut oil. Furthermore, this was the first report on peanut genome editing event, and the obtained high oleic mutants could serve for peanut breeding project.

  14. Lipid accumulation, oxidative stress and immune-related molecules affected by tributyltin exposure in muscle tissues of rare minnow (Gobiocypris rarus).

    PubMed

    Zhang, Jiliang; Zhang, Chunnuan; Ma, Dongdong; Liu, Min; Huang, Shuntao

    2017-12-01

    Tributyltin (TBT) is reported to induce adipogenesis in fish, which might affect nutritional qualities and health status. Muscle tissues account for the majority of body mass, and have been described as a major site of fat deposition and an immunologically active organ. Therefore, the present study aims to evaluate whether chronic exposures of TBT, at environmental concentrations of 1, 10 and 100 ng/L, affects lipid accumulation, oxidative stress and immune status in muscle tissues of rare minnow (Gobiocypris rarus). After 60 d of exposure, TBT increased contents of total lipid, total cholesterol, triglyceride and fatty acids in muscle tissues. Interestingly, TBT exposure disrupted fatty acid composition and increased contents of unsaturated fatty acids (such as eicosapentaenoic acid and docosahexaenoic acid) in muscle tissues, which might be a response to preserve membrane functions from TBT exposure. Meanwhile, the concentrations of hepatic fatty acid desaturase 2 (Δ6-desaturase) and stearoyl-CoA desaturase (Δ9-desaturase) were increased after TBT exposure, which might contribute the increase of unsaturated fatty acids. Furthermore, TBT increased muscle lipid peroxidation products, antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), and the expression of immune-related molecules (tumor necrosis factor alpha, interleukin 1 beta and nuclear factor kappa B) in muscle tissues. The disruption of TBT on the lipid accumulation, oxidative stress and immune-toxic effects in muscle tissues of fish might reduce nutritional qualities, and affect growth and health status, which might pose a constant and serious threat to fish and result in economic loss in aquaculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Rapid-mix and chemical quench studies of ferredoxin-reduced stearoyl-acyl carrier protein desaturase.

    PubMed

    Lyle, Karen S; Haas, Jeffrey A; Fox, Brian G

    2003-05-20

    Stearoyl-ACP Delta9 desaturase (Delta9D) catalyzes the NADPH- and O(2)-dependent insertion of a cis double bond between the C9 and C10 positions of stearoyl-ACP (18:0-ACP) to produce oleoyl-ACP (18:1-ACP). This work revealed the ability of reduced [2Fe-2S] ferredoxin (Fd) to act as a catalytically competent electron donor during the rapid conversion of 18:0-ACP into 18:1-ACP. Experiments on the order of addition for substrate and reduced Fd showed high conversion of 18:0-ACP to 18:1-ACP (approximately 95% per Delta9D active site in a single turnover) when 18:0-ACP was added prior to reduced Fd. Reactions of the prereduced enzyme-substrate complex with O(2) and the oxidized enzyme-substrate complex with reduced Fd were studied by rapid-mix and chemical quench methods. For reaction of the prereduced enzyme-substrate complex, an exponential burst phase (k(burst) = 95 s(-1)) of product formation accounted for approximately 90% of the turnover expected for one subunit in the dimeric protein. This rapid phase was followed by a slower phase (k(linear) = 4.0 s(-1)) of product formation corresponding to the turnover expected from the second subunit. For reaction of the oxidized enzyme-substrate complex with excess reduced Fd, a slower, linear rate (k(obsd) = 3.4 s(-1)) of product formation was observed over approximately 1.5 turnovers per Delta9D active site potentially corresponding to a third phase of reaction. An analysis of the deuterium isotope effect on the two rapid-mix reaction sequences revealed only a modest effect on k(burst) ((D)k(burst) approximately 1.5) and k(linear) (D)k(linear) approximately 1.4), indicating C-H bond cleavage does not contribute significantly to the rate-limiting steps of pre-steady-state catalysis. These results were used to assemble and evaluate a minimal kinetic model for Delta9D catalysis.

  16. Proteasomal degradation of sphingosine kinase 1 and inhibition of dihydroceramide desaturase by the sphingosine kinase inhibitors, SKi or ABC294640, induces growth arrest in androgen-independent LNCaP-AI prostate cancer cells.

    PubMed

    McNaughton, Melissa; Pitman, Melissa; Pitson, Stuart M; Pyne, Nigel J; Pyne, Susan

    2016-03-29

    Sphingosine kinases (two isoforms termed SK1 and SK2) catalyse the formation of the bioactive lipid sphingosine 1-phosphate. We demonstrate here that the SK2 inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) or the SK1/SK2 inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) induce the proteasomal degradation of SK1a (Mr = 42 kDa) and inhibit DNA synthesis in androgen-independent LNCaP-AI prostate cancer cells. These effects are recapitulated by the dihydroceramide desaturase (Des1) inhibitor, fenretinide. Moreover, SKi or ABC294640 reduce Des1 activity in Jurkat cells and ABC294640 induces the proteasomal degradation of Des1 (Mr = 38 kDa) in LNCaP-AI prostate cancer cells. Furthermore, SKi or ABC294640 or fenretinide increase the expression of the senescence markers, p53 and p21 in LNCaP-AI prostate cancer cells. The siRNA knockdown of SK1 or SK2 failed to increase p53 and p21 expression, but the former did reduce DNA synthesis in LNCaP-AI prostate cancer cells. Moreover, N-acetylcysteine (reactive oxygen species scavenger) blocked the SK inhibitor-induced increase in p21 and p53 expression but had no effect on the proteasomal degradation of SK1a. In addition, siRNA knockdown of Des1 increased p53 expression while a combination of Des1/SK1 siRNA increased the expression of p21. Therefore, Des1 and SK1 participate in regulating LNCaP-AI prostate cancer cell growth and this involves p53/p21-dependent and -independent pathways. Therefore, we propose targeting androgen-independent prostate cancer cells with compounds that affect Des1/SK1 to modulate both de novo and sphingolipid rheostat pathways in order to induce growth arrest.

  17. Gene Expression of Desaturase (FADS1 and FADS2) and Elongase (ELOVL5) Enzymes in Peripheral Blood: Association with Polyunsaturated Fatty Acid Levels and Atopic Eczema in 4-Year-Old Children

    PubMed Central

    Chisaguano, Aida Maribel; Montes, Rosa; Pérez-Berezo, Teresa; Castellote, Ana Isabel; Guerendiain, Marcela; Bustamante, Mariona; Morales, Eva; García-Esteban, Raquel; Sunyer, Jordi; Franch, Àngels; López-Sabater, M. Carmen

    2013-01-01

    Abstract Background It is unknown if changes in the gene expression of the desaturase and elongase enzymes are associated with abnormal n-6 long chain polyunsaturated fatty acid (LC-PUFA) levels in children with atopic eczema (AE). We analyzed whether mRNA-expression of genes encoding key enzymes of LC-PUFA synthesis (FADS1, FADS2 and ELOVL5) is associated with circulating LC-PUFA levels and risk of AE in 4-year-old children. Methods AE (n=20) and non-AE (n=104) children participating in the Sabadell cohort within the INfancia y Medio Ambiente (INMA) Project were included in the present study. RT-PCR with TaqMan Low-Density Array cards was used to measure the mRNA-expression of FADS1, FADS2 and ELOVL5. LC-PUFA levels were measured by fast gas chromatography in plasma phospholipids. The relationship of gene expression with LC-PUFA levels and enzyme activities was evaluated by Pearson’s rank correlation coefficient, and logistic regression models were used to study its association with risk of developing AE. Results Children with AE had lower levels of several n-6 PUFA members, dihomo-γ-linolenic (DGLA) and arachidonic (AA) acids. mRNA-expression levels of FADS1 and 2 strongly correlated with DGLA levels and with D6D activity. FADS2 and ELOVL5 mRNA-expression levels were significantly lower in AE than in non-AE children (-40.30% and -20.36%; respectively), but no differences were found for FADS1. Conclusions and Significance Changes in the mRNA-expression levels of FADS1 and 2 directly affect blood DGLA levels and D6D activity. This study suggests that lower mRNA-expressions of FADS2 and ELOVL5 are associated with higher risk of atopic eczema in young children. PMID:24167612

  18. Gene expression of desaturase (FADS1 and FADS2) and Elongase (ELOVL5) enzymes in peripheral blood: association with polyunsaturated fatty acid levels and atopic eczema in 4-year-old children.

    PubMed

    Chisaguano, Aida Maribel; Montes, Rosa; Pérez-Berezo, Teresa; Castellote, Ana Isabel; Guerendiain, Marcela; Bustamante, Mariona; Morales, Eva; García-Esteban, Raquel; Sunyer, Jordi; Franch, Angels; López-Sabater, M Carmen

    2013-01-01

    It is unknown if changes in the gene expression of the desaturase and elongase enzymes are associated with abnormal n-6 long chain polyunsaturated fatty acid (LC-PUFA) levels in children with atopic eczema (AE). We analyzed whether mRNA-expression of genes encoding key enzymes of LC-PUFA synthesis (FADS1, FADS2 and ELOVL5) is associated with circulating LC-PUFA levels and risk of AE in 4-year-old children. AE (n=20) and non-AE (n=104) children participating in the Sabadell cohort within the INfancia y Medio Ambiente (INMA) Project were included in the present study. RT-PCR with TaqMan Low-Density Array cards was used to measure the mRNA-expression of FADS1, FADS2 and ELOVL5. LC-PUFA levels were measured by fast gas chromatography in plasma phospholipids. The relationship of gene expression with LC-PUFA levels and enzyme activities was evaluated by Pearson's rank correlation coefficient, and logistic regression models were used to study its association with risk of developing AE. Children with AE had lower levels of several n-6 PUFA members, dihomo-γ-linolenic (DGLA) and arachidonic (AA) acids. mRNA-expression levels of FADS1 and 2 strongly correlated with DGLA levels and with D6D activity. FADS2 and ELOVL5 mRNA-expression levels were significantly lower in AE than in non-AE children (-40.30% and -20.36%; respectively), but no differences were found for FADS1. Changes in the mRNA-expression levels of FADS1 and 2 directly affect blood DGLA levels and D6D activity. This study suggests that lower mRNA-expressions of FADS2 and ELOVL5 are associated with higher risk of atopic eczema in young children.

  19. Alcoholic liver disease.

    PubMed

    Penny, Steven M

    2013-01-01

    In the United States, approximately 100,000 deaths are attributed to alcohol abuse each year. In 2009, the World Health Organization listed alcohol use as one of the leading causes of the global burden of disease and injury. Alcoholic liver disease, a direct result of chronic alcohol abuse, insidiously destroys the normal functions of the liver. The end result of the disease, cirrhosis, culminates in a dysfunctional and diffusely scarred liver. This article discusses the clinical manifestations, imaging considerations, and treatment of alcoholic liver disease and cirrhosis. Normal liver function, liver hemodynamics, the disease of alcoholism, and the deleterious effects of alcohol also are reviewed.

  20. Biomarkers for liver fibrosis

    DOEpatents

    Jacobs, Jon M.; Burnum-Johnson, Kristin E.; Baker, Erin M.; Smith, Richard D.; Gritsenko, Marina A.; Orton, Daniel

    2017-05-16

    Methods and systems for diagnosing or prognosing liver fibrosis in a subject are provided. In some examples, such methods and systems can include detecting liver fibrosis-related molecules in a sample obtained from the subject, comparing expression of the molecules in the sample to controls representing expression values expected in a subject who does not have liver fibrosis or who has non-progressing fibrosis, and diagnosing or prognosing liver fibrosis in the subject when differential expression of the molecules between the sample and the controls is detected. Kits for the diagnosis or prognosis of liver fibrosis in a subject are also provided which include reagents for detecting liver fibrosis related molecules.

  1. Biomarkers for liver fibrosis

    DOEpatents

    Jacobs, Jon M.; Burnum-Johnson, Kristin E.; Baker, Erin M.; Smith, Richard D.; Gritsenko, Marina A.; Orton, Daniel

    2015-09-15

    Methods and systems for diagnosing or prognosing liver fibrosis in a subject are provided. In some examples, such methods and systems can include detecting liver fibrosis-related molecules in a sample obtained from the subject, comparing expression of the molecules in the sample to controls representing expression values expected in a subject who does not have liver fibrosis or who has non-progressing fibrosis, and diagnosing or prognosing liver fibrosis in the subject when differential expression of the molecules between the sample and the controls is detected. Kits for the diagnosis or prognosis of liver fibrosis in a subject are also provided which include reagents for detecting liver fibrosis related molecules.

  2. 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

  3. Identification and characterization of a plastidial ω-3 fatty acid desaturase EgFAD8 from oil palm (Elaeis guineensis Jacq.) and its promoter response to light and low temperature

    PubMed Central

    Chen, Lizhi; Wang, Lei; Wang, Herong; Sun, Ruhao; You, Lili; Zheng, Yusheng; Yuan, Yijun

    2018-01-01

    In higher plants, ω-3 fatty acid desaturases are the key enzymes in the biosynthesis of alpha-linolenic acid (18:3), which plays key roles in plant metabolism as a structural component of both storage and membrane lipids. Here, the first ω-3 fatty acid desaturase gene was identified and characterized from oil palm. The bioinformatic analysis indicated it encodes a temperature-sensitive chloroplast ω-3 fatty acid desaturase, designated as EgFAD8. The expression analysis revealed that EgFAD8 is highly expressed in the oil palm leaves, when compared with the expression in the mesocarp. The heterologous expression of EgFAD8 in yeast resulted in the production of a novel fatty acid 18:3 (about 0.27%), when fed with 18:2 in the induction culture. Furthermore, to detect whether EgFAD8 could be induced by the environment stress, we detected the expression efficiency of the EgFAD8 promoter in transgenic Arabidopsis treated with low temperature and darkness, respectively. The results indicated that the promoter of EgFAD8 gene could be significantly induced by low temperature and slightly induced by darkness. These results reveal the function of EgFAD8 and the feature of its promoter from oil palm fruits, which will be useful for understanding the fuction and regulation of plastidial ω-3 fatty acid desaturases in higher plants. PMID:29698515

  4. 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

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

    2017-03-21

    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 ≥ C 18 chain lengths. Scd was unable to desaturate 20:1 n- 15 ( ∆5 20:1) 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 20:1 n- 9 ( ∆11 20:1) to ∆5,11 20:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5 n- 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 (>C 24 ) PUFAs.

  5. Azide and acetate complexes plus two iron-depleted crystal structures of the di-iron enzyme delta9 stearoyl-acyl carrier protein desaturase. Implications for oxygen activation and catalytic intermediates.

    PubMed

    Moche, Martin; Shanklin, John; Ghoshal, Alokesh; Lindqvist, Ylva

    2003-07-04

    Delta9 stearoyl-acyl carrier protein (ACP) desaturase is a mu-oxo-bridged di-iron enzyme, which belongs to the structural class I of large helix bundle proteins and that catalyzes the NADPH and O2-dependent formation of a cis-double bond in stearoyl-ACP. The crystal structures of complexes with azide and acetate, respectively, as well as the apoand single-iron forms of Delta9 stearoyl-ACP desaturase from Ricinus communis have been determined. In the azide complex, the ligand forms a mu-1,3-bridge between the two iron ions in the active site, replacing a loosely bound water molecule. The structure of the acetate complex is similar, with acetate bridging the di-iron center in the same orientation with respect to the di-iron center. However, in this complex, the iron ligand Glu196 has changed its coordination mode from bidentate to monodentate, the first crystallographic observation of a carboxylate shift in Delta9 stearoyl-ACP desaturase. The two complexes are proposed to mimic a mu-1,2 peroxo intermediate present during catalytic turnover. There are striking structural similarities between the di-iron center in the Delta9 stearoyl-ACP desaturase-azide complex and in the reduced rubrerythrin-azide complex. This suggests that Delta9 stearoyl-ACP desaturase might catalyze the formation of water from exogenous hydrogen peroxide at a low rate. From the similarity in iron center structure, we propose that the mu-oxo-bridge in oxidized desaturase is bound to the di-iron center as in rubrerythrin and not as reported for the R2 subunit of ribonucleotide reductase and the hydroxylase subunit of methane monooxygenase. The crystal structure of the one-iron depleted desaturase species demonstrates that the affinities for the two iron ions comprising the di-iron center are not equivalent, Fe1 being the higher affinity site and Fe2 being the lower affinity site.

  6. Bioartificial liver: current status.

    PubMed

    Pless, G; Sauer, I M

    2005-11-01

    Liver failure remains a life-threatening syndrome. With the growing disparity between the number of suitable donor organs and the number of patients awaiting transplantation, efforts have been made to optimize the allocation of organs, to find alternatives to cadaveric liver transplantation, and to develop extracorporeal methods to support or replace the function of the failing organ. An extracorporeal liver support system has to provide the main functions of the liver: detoxification, synthesis, and regulation. The understanding that the critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver led to the development of artificial filtration and adsorption devices (artificial liver support). Based on this hypothesis, the removal of lipophilic, albumin-bound substances, such as bilirubin, bile acids, metabolites of aromatic amino acids, medium-chain fatty acids, and cytokines, should be beneficial to the clinical course of a patient in liver failure. Artificial detoxification devices currently under clinical evaluation include the Molecular Adsorbent Recirculating System (MARS), Single-Pass Albumin Dialysis (SPAD), and the Prometheus system. The complex tasks of regulation and synthesis remain to be addressed by the use of liver cells (bioartificial liver support). The Extracorporeal Liver Assist Device (ELAD), HepatAssist, Modular Extracorporeal Liver Support system (MELS), and the Amsterdam Medical Center Bioartificial Liver (AMC-BAL) are bioartificial systems. This article gives a brief overview on these artificial and bioartificial devices and discusses remaining obstacles.

  7. Effects of the liver volume and donor steatosis on errors in the estimated standard liver volume.

    PubMed

    Siriwardana, Rohan Chaminda; Chan, See Ching; Chok, Kenneth Siu Ho; Lo, Chung Mau; Fan, Sheung Tat

    2011-12-01

    An accurate assessment of donor and recipient liver volumes is essential in living donor liver transplantation. Many liver donors are affected by mild to moderate steatosis, and steatotic livers are known to have larger volumes. This study analyzes errors in liver volume estimation by commonly used formulas and the effects of donor steatosis on these errors. Three hundred twenty-five Asian donors who underwent right lobe donor hepatectomy were the subjects of this study. The percentage differences between the liver volumes from computed tomography (CT) and the liver volumes estimated with each formula (ie, the error percentages) were calculated. Five popular formulas were tested. The degrees of steatosis were categorized as follows: no steatosis [n = 178 (54.8%)], ≤ 10% steatosis [n = 128 (39.4%)], and >10% to 20% steatosis [n = 19 (5.8%)]. The median errors ranged from 0.6% (7 mL) to 24.6% (360 mL). The lowest was seen with the locally derived formula. All the formulas showed a significant association between the error percentage and the CT liver volume (P < 0.001). Overestimation was seen with smaller liver volumes, whereas underestimation was seen with larger volumes. The locally derived formula was most accurate when the liver volume was 1001 to 1250 mL. A multivariate analysis showed that the estimation error was dependent on the liver volume (P = 0.001) and the anthropometric measurement that was used in the calculation (P < 0.001) rather than steatosis (P ≥ 0.07). In conclusion, all the formulas have a similar pattern of error that is possibly related to the anthropometric measurement. Clinicians should be aware of this pattern of error and the liver volume with which their formula is most accurate. Copyright © 2011 American Association for the Study of Liver Diseases.

  8. Liver transplantation for metastatic liver malignancies.

    PubMed

    Foss, Aksel; Lerut, Jan P

    2014-06-01

    Liver transplantation is a validated treatment of primary hepatobiliary tumours. Over the last decade, a renewed interest for liver transplantation as a curative treatment of colorectal liver metastasis (CR-LM) and neuro-endocrine metastasis (NET-LM) has developed. The ELTR and UNOS analyses showed that liver transplantation may offer excellent disease-free survival (ranging from 30 to 77%) in case of NET-LM, on the condition that stringent selection criteria are implemented. The interest for liver transplantation in the treatment of CR-LM has been fostered by the Norwegian SECA study. Five-year A 5-year survival rate of 60% could be reached. Despite the high recurrence rate (90%), one-third of patients were disease free following pulmonary surgery for metastases. Liver transplantation will take a more prominent place in the therapeutic algorithm of CR-LM and NET-LM. Larger experiences are necessary to improve knowledge about tumour biology and to refine selection criteria. A multimodal approach adding neo and adjuvant medical treatment to the transplant procedure will be key to bring this oncologic transplant project into the clinical arena. The preserved liver function in these patients will allow a more deliberate access to split liver and living donation for these indications.

  9. Interaction between periodontitis and liver diseases

    PubMed Central

    Han, Pengyu; Sun, Dianxing; Yang, Jie

    2016-01-01

    Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue. PMID:27588170

  10. Effects of cortisone on regenerating rat liver.

    PubMed

    EINHORN, S L; HIRSCHBERG, E; GELLHORN, A

    1954-03-01

    The effects of continuous administration of cortisone on the metabolism of regenerating rat liver have been studied. Whereas the restoration of the weight of the liver after partial hepatectomy was not markedly affected by cortisone, the multiplication of cells was reduced to a significant degree after the first 2 days of regeneration. Liver restoration in terms of nucleic acids was similarly inhibited by cortisone. The results are consistent with the interpretation that the inhibition of cell multiplication in this system is dependent on and keeps pace with the inhibition of nucleic acid synthesis by this drug. At almost any time after hepatectomy, the nucleic acid content of the liver cells was the same in treated and in untreated animals. In ancillary studies, it was shown that cortisone caused the cells of regenerating liver to be increased in size and weight through the increased infiltration of lipids. Changes in water, protein, and carbohydrate content of the liver cells did not contribute to this increase in the weight of the cells. Since all animals were treated with cortisone for 5 days before hepatectomy, data were also obtained on the effect of this agent on the resting liver. This course of treatment brought about a significant decrease in the number of cells per unit wet weight and in the water content of the livers. The nucleic acid content of the cells at hepatectomy, on the other hand, was unchanged.

  11. [Schizophrenia and Liver Transplantation: Case Report].

    PubMed

    Diana, Restrepo B; Marle, Duque G; Carlos, Cardeño C

    2012-09-01

    Liver transplantation is a treatment available for many patients with liver cirrhosis who find in this treatment a way to improve life expectancy and quality of life. Paranoid schizophrenia affects 1% of the general population, produces psychotic symptoms, and runs a chronic course in some cases with significant deterioration in all areas of life. To discuss the case of a patient with liver cirrhosis diagnosed with paranoid schizophrenia during the evaluation protocol for liver transplantation. Case report. We report the case of a 47-year-old woman with liver cirrhosis whose only alternative to improve life expectancy and quality of life was access to liver transplantation. During routine evaluations the liaison psychiatrist observed first-order psychotic symptoms and documented a life story that confirmed the presence of paranoid schizophrenia. Paranoid schizophrenia is a psychiatric disorder common in the general population that can be a part of the medical comorbidities of patients requiring liver transplantation and is not an absolute contraindication to its completion. We are unaware of similar cases of liver transplantation in patients with schizophrenia in our country. We believe this is a big step on the road to overcome the stigma that mental illness imposes on patients. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  12. Role of Gut Microbiota in Liver Disease.

    PubMed

    Brenner, David A; Paik, Yong-Han; Schnabl, Bernd

    2015-01-01

    Many lines of research have established a relationship between the gut microbiome and patients with liver disease. For example, patients with cirrhosis have increased bacteremia, increased blood levels of lipopolysaccharide, and increased intestinal permeability. Patients with cirrhosis have bacterial overgrowth in the small intestine. Selective intestinal decontamination with antibiotics is beneficial for patients with decompensated cirrhosis. In experimental models of chronic liver injury with fibrosis, several toll-like receptors (TLR) are required to make mice sensitive to liver fibrosis. The presumed ligand for the TLRs are bacterial products derived from the gut microbiome, and TLR knockout mice are resistant to liver inflammation and fibrosis. We and others have characterized the association between preclinical models of liver disease in mice with the microbial diversity in their gut microbiome. In each model, including intragastric alcohol, bile duct ligation, chronic carbon tetrachloride (CCl4), administration, and genetic obesity, there is a significant change in the gut microbiome from normal control mice. However, there is not a single clear bacterial strain or pattern that distinguish mice with liver injury from controlled mice. So how can the gut microbiota affect liver disease? We can identify at least 6 changes that would result in liver injury, inflammation, and/or fibrosis. These include: (1) changes in caloric yield of diet; (2) regulation of gut permeability to release bacterial products; (3) modulation of choline metabolism; (4) production of endogenous ethanol; (5) regulation of bile acid metabolism; and (6) regulation in lipid metabolism.

  13. The effects of space flight on some rat liver enzymes regulating carbohydrate and lipid metabolism

    NASA Technical Reports Server (NTRS)

    Abraham, S.; Lin, C. Y.; Klein, H. P.; Volkmann, C.

    1981-01-01

    The effects of space flight conditions on the activities of certain enzymes regulating carbohydrate and lipid metabolism in rat liver are investigated in an attempt to account for the losses in body weight observed during space flight despite preflight caloric consumption. Liver samples were analyzed for the activities of 32 cytosolic and microsomal enzymes as well as hepatic glycogen and individual fatty acid levels for ground control rats and rats flown on board the Cosmos 936 biosatellite under normal space flight conditions and in centrifuges which were sacrificed upon recovery or 25 days after recovery. Significant decreases in the activities of glycogen phosphorylase, alpha-glycerol phosphate acyl transferase, diglyceride acyl transferase, aconitase and 6-phosphogluconate dehydrogenase and an increase in palmitoyl CoA desaturase are found in the flight stationary relative to the flight contrifuged rats upon recovery, with all enzymes showing alterations returning to normal values 25 days postflight. The flight stationary group is also observed to be characterized by more than twice the amount of liver glycogen of the flight centrifuged group as well as a significant increase in the ratio of palmitic to palmitoleic acid. Results thus indicate metabolic changes which may be involved in the mechanism of weight loss during weightlessness, and demonstrate the equivalence of centrifugation during space flight to terrestrial gravity.

  14. Amebic liver abscess

    MedlinePlus

    ... abscess URL of this page: //medlineplus.gov/ency/article/000211.htm Amebic liver abscess To use the sharing features on this page, please enable JavaScript. Amebic liver abscess is a collection of pus ...

  15. Antioxidants in liver health

    PubMed Central

    Casas-Grajales, Sael; Muriel, Pablo

    2015-01-01

    Liver diseases are a worldwide medical problem because the liver is the principal detoxifying organ and maintains metabolic homeostasis. The liver metabolizes various compounds that produce free radicals (FR). However, antioxidants scavenge FR and maintain the oxidative/antioxidative balance in the liver. When the liver oxidative/antioxidative balance is disrupted, the state is termed oxidative stress. Oxidative stress leads to deleterious processes in the liver and produces liver diseases. Therefore, restoring antioxidants is essential to maintain homeostasis. One method of restoring antioxidants is to consume natural compounds with antioxidant capacity. The objective of this review is to provide information pertaining to various antioxidants found in food that have demonstrated utility in improving liver diseases. PMID:26261734

  16. Liver Transplant: Nutrition

    MedlinePlus

    ... transplant and liver disease patients. Pre-Transplant Protein Malnutrition -- Many patients with end stage liver disease do ... to lose weight sensibly and slowly, without causing malnutrition (especially protein malnutrition). Losing excess weight decreases the ...

  17. Perioperative Care of the Liver Transplant Patient.

    PubMed

    Keegan, Mark T; Kramer, David J

    2016-07-01

    With the evolution of surgical and anesthetic techniques, liver transplantation has become "routine," allowing for modifications of practice to decrease perioperative complications and costs. There is debate over the necessity for intensive care unit admission for patients with satisfactory preoperative status and a smooth intraoperative course. Postoperative care is made easier when the liver graft performs optimally. Assessment of graft function, vigilance for complications after the major surgical insult, and optimization of multiple systems affected by liver disease are essential aspects of postoperative care. The intensivist plays a vital role in an integrated multidisciplinary transplant team. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Microbiota and the liver.

    PubMed

    Shen, Ting-Chin David; Pyrsopoulos, Nikolaos; Rustgi, Vinod K

    2018-04-01

    The gut microbiome outnumbers the human genome by 150-fold and plays important roles in metabolism, immune system education, tolerance development, and prevention of pathogen colonization. Dysbiosis has been associated with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), and alcoholic liver disease (ALD) as well as cirrhosis and complications. This article provides an overview of this relationship. Liver Transplantation 24 539-550 2018 AASLD. © 2018 by the American Association for the Study of Liver Diseases.

  19. Stages of Childhood Liver Cancer

    MedlinePlus

    ... Liver Cancer Prevention Liver Cancer Screening Research Childhood Liver Cancer Treatment (PDQ®)–Patient Version Treatment Option Overview Go ... different types of treatment for patients with childhood liver cancer. Different types of treatments are available for children ...

  20. Forms of n-3 (ALA, C18:3n-3 or DHA, C22:6n-3) Fatty Acids Affect Carcass Yield, Blood Lipids, Muscle n-3 Fatty Acids and Liver Gene Expression in Lambs.

    PubMed

    Ponnampalam, Eric N; Lewandowski, Paul A; Fahri, Fahri T; Burnett, Viv F; Dunshea, Frank R; Plozza, Tim; Jacobs, Joe L

    2015-11-01

    The effects of supplementing diets with n-3 alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) on plasma metabolites, carcass yield, muscle n-3 fatty acids and liver messenger RNA (mRNA) in lambs were investigated. Lambs (n = 120) were stratified to 12 groups based on body weight (35 ± 3.1 kg), and within groups randomly allocated to four dietary treatments: basal diet (BAS), BAS with 10.7 % flaxseed supplement (Flax), BAS with 1.8 % algae supplement (DHA), BAS with Flax and DHA (FlaxDHA). Lambs were fed for 56 days. Blood samples were collected on day 0 and day 56, and plasma analysed for insulin and lipids. Lambs were slaughtered, and carcass traits measured. At 30 min and 24 h, liver and muscle samples, respectively, were collected for determination of mRNA (FADS1, FADS2, CPT1A, ACOX1) and fatty acid composition. Lambs fed Flax had higher plasma triacylglycerol, body weight, body fat and carcass yield compared with the BAS group (P < 0.001). DHA supplementation increased carcass yield and muscle DHA while lowering plasma insulin compared with the BAS diet (P < 0.01). Flax treatment increased (P < 0.001) muscle ALA concentration, while DHA treatment increased (P < 0.001) muscle DHA concentration. Liver mRNA FADS2 was higher and CPT1A lower in the DHA group (P < 0.05). The FlaxDHA diet had additive effects, including higher FADS1 and ACOX1 mRNA than for the Flax or DHA diet. In summary, supplementation with ALA or DHA modulated plasma metabolites, muscle DHA, body fat and liver gene expression differently.

  1. Morphology and morphometry of fetal liver at 16-26 weeks of gestation by magnetic resonance imaging: Comparison with embryonic liver at Carnegie stage 23.

    PubMed

    Hamabe, Yui; Hirose, Ayumi; Yamada, Shigehito; Uwabe, Chigako; Okada, Tomohisa; Togashi, Kaori; Kose, Katsumi; Takakuwa, Tetsuya

    2013-06-01

    Normal liver growth was described morphologically and morphometrically using magnetic resonance imaging (MRI) data of human fetuses, and compared with embryonic liver to establish a normal reference chart for clinical use. MRI images from 21 fetuses at 16-26 weeks of gestation and eight embryos at Carnegie stage (CS)23 were investigated in the present study. Using the image data, the morphology of the liver as well as its adjacent organs was extracted and reconstructed three-dimensionally. Morphometry of fetal liver growth was performed using simple regression analysis. The fundamental morphology was similar in all cases of the fetal livers examined. The liver tended to grow along the transversal axis. The four lobes were clearly recognizable in the fetal liver but not in the embryonic liver. The length of the liver along the three axes, liver volume and four lobes correlated with the bodyweight (BW). The morphogenesis of the fetal liver on the dorsal and caudal sides was affected by the growth of the abdominal organs, such as the stomach, duodenum and spleen, and retroperitoneal organs, such as the right adrenal gland and right kidney. The main blood vessels such as inferior vena cava, portal vein and umbilical vein made a groove on the surface of the liver. Morphology of the fetal liver was different from that of the embryonic liver at CS23. The present data will be useful for evaluating the development of the fetal liver and the adjacent organs that affect its morphology. © 2012 The Japan Society of Hepatology.

  2. Augmenter of Liver Regeneration (alr) Promotes Liver Outgrowth during Zebrafish Hepatogenesis

    PubMed Central

    Li, Yan; Farooq, Muhammad; Sheng, Donglai; Chandramouli, Chanchal; Lan, Tian; Mahajan, Nilesh K.; Kini, R. Manjunatha; Hong, Yunhan; Lisowsky, Thomas; Ge, Ruowen

    2012-01-01

    Augmenter of Liver Regeneration (ALR) is a sulfhydryl oxidase carrying out fundamental functions facilitating protein disulfide bond formation. In mammals, it also functions as a hepatotrophic growth factor that specifically stimulates hepatocyte proliferation and promotes liver regeneration after liver damage or partial hepatectomy. Whether ALR also plays a role during vertebrate hepatogenesis is unknown. In this work, we investigated the function of alr in liver organogenesis in zebrafish model. We showed that alr is expressed in liver throughout hepatogenesis. Knockdown of alr through morpholino antisense oligonucleotide (MO) leads to suppression of liver outgrowth while overexpression of alr promotes liver growth. The small-liver phenotype in alr morphants results from a reduction of hepatocyte proliferation without affecting apoptosis. When expressed in cultured cells, zebrafish Alr exists as dimer and is localized in mitochondria as well as cytosol but not in nucleus or secreted outside of the cell. Similar to mammalian ALR, zebrafish Alr is a flavin-linked sulfhydryl oxidase and mutation of the conserved cysteine in the CxxC motif abolishes its enzymatic activity. Interestingly, overexpression of either wild type Alr or enzyme-inactive AlrC131S mutant promoted liver growth and rescued the liver growth defect of alr morphants. Nevertheless, alr C131S is less efficacious in both functions. Meantime, high doses of alr MOs lead to widespread developmental defects and early embryonic death in an alr sequence-dependent manner. These results suggest that alr promotes zebrafish liver outgrowth using mechanisms that are dependent as well as independent of its sulfhydryl oxidase activity. This is the first demonstration of a developmental role of alr in vertebrate. It exemplifies that a low-level sulfhydryl oxidase activity of Alr is essential for embryonic development and cellular survival. The dose-dependent and partial suppression of alr expression through MO

  3. Application of Induced Pluripotent Stem Cells in Liver Diseases

    PubMed Central

    Yu, Yue; Wang, Xuehao; Nyberg, Scott L.

    2014-01-01

    Tens of millions of patients are affected by liver disease worldwide. Many of these patients can benefit from therapy involving hepatocyte transplantation. Liver transplantation is presently the only proven treatment for many medically refractory liver diseases including end-stage liver failure and inherited metabolic liver disease. However, the shortage in transplantable livers prevents over 40% of listed patients per year from receiving a liver transplant; many of these patients die before receiving an organ offer or become too sick to transplant. Therefore, new therapies are needed to supplement whole-organ liver transplantation and reduce mortality on waiting lists worldwide. Furthermore, the remarkable regenerative capacity of hepatocytes in vivo is exemplified by the increasing number of innovative cell-based therapies and animal models of human liver disorders. Induced pluripotent stem cells (iPSCs) have similar properties to those of embryonic stem cells (ESCs) but bypass the ethical concerns of embryo destruction. Therefore, generation of hepatocyte-like cells (HLCs) using iPSC technology may be beneficial for the treatment of severe liver diseases, screening of drug toxicities, basic research of several hepatocytic disorders, and liver transplantation. Here we briefly summarize the growing number of potential applications of iPSCs for treatment of liver disease. PMID:26858888

  4. Coffee and Liver Disease.

    PubMed

    Wadhawan, Manav; Anand, Anil C

    2016-03-01

    Coffee is the most popular beverage in the world. Consumption of coffee has been shown to benefit health in general, and liver health in particular. This article reviews the effects of coffee intake on development and progression of liver disease due to various causes. We also describe the putative mechanisms by which coffee exerts the protective effect. The clinical evidence of benefit of coffee consumption in Hepatitis B and C, as well as nonalcoholic fatty liver disease and alcoholic liver disease, has also been presented. Coffee consumption is associated with improvement in liver enzymes (ALT, AST, and GGTP), especially in individuals with risk for liver disease. Coffee intake more than 2 cups per day in patients with preexisting liver disease has been shown to be associated with lower incidence of fibrosis and cirrhosis, lower hepatocellular carcinoma rates, as well as decreased mortality.

  5. FXR and liver carcinogenesis

    PubMed Central

    Huang, Xiong-fei; Zhao, Wei-yu; Huang, Wen-dong

    2015-01-01

    Farnesoid X receptor (FXR) is a member of the nuclear receptor family and a ligand-modulated transcription factor. In the liver, FXR has been considered a multi-functional cell protector and a tumor suppressor. FXR can suppress liver carcinogenesis via different mechanisms: 1) FXR maintains the normal liver metabolism of bile acids, glucose and lipids; 2) FXR promotes liver regeneration and repair after injury; 3) FXR protects liver cells from death and enhances cell survival; 4) FXR suppresses hepatic inflammation, thereby preventing inflammatory damage; and 5) FXR can directly increase the expression of some tumor-suppressor genes and repress the transcription of several oncogenes. However, inflammation and epigenetic silencing are known to decrease FXR expression during tumorigenesis. The reactivation of FXR function in the liver may be a potential therapeutic approach for patients with liver cancer. PMID:25500874

  6. Expression of phytoene synthase1 and carotene desaturase crtI genes result in an increase in the total carotenoids content in transgenic elite wheat (Triticum aestivum L.).

    PubMed

    Cong, Ling; Wang, Cheng; Chen, Ling; Liu, Huijuan; Yang, Guangxiao; He, Guangyuan

    2009-09-23

    Dietary micronutrient deficiencies, such as the lack of vitamin A, are a major source of morbidity and mortality worldwide. Carotenoids in food can function as provitamin A in humans, while grains of Chinese elite wheat cultivars generally have low carotenoid contents. To increase the carotenoid contents in common wheat endosperm, transgenic wheat has been generated by expressing the maize y1 gene encoding phytoene synthase driven by a endosperm-specific 1Dx5 promoter in the elite wheat (Triticum aestivum L.) variety EM12, together with the bacterial phytoene desaturase crtI gene from Erwinia uredovora under the constitutive CaMV 35S promoter control. A clear increase of the carotenoid content was detected in the endosperms of transgenic wheat that visually showed a light yellow color. The total carotenoids content was increased up to 10.8-fold as compared with the nontransgenic EM12 cultivar. To test whether the variability of total carotenoid content in different transgenic lines was due to differences in the transgene copy number or expression pattern, Southern hybridization and semiquantitative reverse transcriptase polymerase chain reaction analyses were curried out. The results showed that transgene copy numbers and transcript levels did not associate well with carotenoid contents. The expression patterns of endogenous carotenoid genes, such as the phytoene synthases and carotene desaturases, were also investigated in wild-type and transgenic wheat lines. No significant changes in expression levels of these genes were detected in the transgenic endosperms, indicating that the increase in carotenoid transgenic wheat endosperms resulted from the expression of transgenes.

  7. Omega-3 fatty acid desaturase gene family from two ω-3 sources, Salvia hispanica and Perilla frutescens: Cloning, characterization and expression

    PubMed Central

    Xue, Yufei; Chen, Baojun; Win, Aung Naing; Fu, Chun; Lian, Jianping; Liu, Xue; Wang, Rui; Zhang, Xingcui

    2018-01-01

    Omega-3 fatty acid desaturase (ω-3 FAD, D15D) is a key enzyme for α-linolenic acid (ALA) biosynthesis. Both chia (Salvia hispanica) and perilla (Perilla frutescens) contain high levels of ALA in seeds. In this study, the ω-3 FAD gene family was systematically and comparatively cloned from chia and perilla. Perilla FAD3, FAD7, FAD8 and chia FAD7 are encoded by single-copy (but heterozygous) genes, while chia FAD3 is encoded by 2 distinct genes. Only 1 chia FAD8 sequence was isolated. In these genes, there are 1 to 6 transcription start sites, 1 to 8 poly(A) tailing sites, and 7 introns. The 5’UTRs of PfFAD8a/b contain 1 to 2 purine-stretches and 2 pyrimidine-stretches. An alternative splice variant of ShFAD7a/b comprises a 5’UTR intron. Their encoded proteins harbor an FA_desaturase conserved domain together with 4 trans-membrane helices and 3 histidine boxes. Phylogenetic analysis validated their identity of dicot microsomal or plastidial ω-3 FAD proteins, and revealed some important evolutionary features of plant ω-3 FAD genes such as convergent evolution across different phylums, single-copy status in algae, and duplication events in certain taxa. The qRT-PCR assay showed that the ω-3 FAD genes of two species were expressed at different levels in various organs, and they also responded to multiple stress treatments. The functionality of the ShFAD3 and PfFAD3 enzymes was confirmed by yeast expression. The systemic molecular and functional features of the ω-3 FAD gene family from chia and perilla revealed in this study will facilitate their use in future studies on genetic improvement of ALA traits in oilseed crops. PMID:29351555

  8. 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.

  9. 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.

  10. Polymorphisms in Fatty Acid Desaturase (FADS) Gene Cluster: Effects on Glycemic Controls Following an Omega-3 Polyunsaturated Fatty Acids (PUFA) Supplementation

    PubMed Central

    Cormier, Hubert; Rudkowska, Iwona; Thifault, Elisabeth; Lemieux, Simone; Couture, Patrick; Vohl, Marie-Claude

    2013-01-01

    Changes in desaturase activity are associated with insulin sensitivity and may be associated with type 2 diabetes mellitus (T2DM). Polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster have been associated with the homeostasis model assessment of insulin sensitivity (HOMA-IS) and serum fatty acid composition. Objective: To investigate whether common genetic variations in the FADS gene cluster influence fasting glucose (FG) and fasting insulin (FI) responses following a 6-week n-3 polyunsaturated fatty acids (PUFA) supplementation. Methods: 210 subjects completed a 2-week run-in period followed by a 6-week supplementation with 5 g/d of fish oil (providing 1.9 g–2.2 g of EPA + 1.1 g of DHA). Genotyping of 18 SNPs of the FADS gene cluster covering 90% of all common genetic variations (minor allele frequency ≥ 0.03) was performed. Results: Carriers of the minor allele for rs482548 (FADS2) had increased plasma FG levels after the n-3 PUFA supplementation in a model adjusted for FG levels at baseline, age, sex, and BMI. A significant genotype*supplementation interaction effect on FG levels was observed for rs482548 (p = 0.008). For FI levels, a genotype effect was observed with one SNP (rs174456). For HOMA-IS, several genotype*supplementation interaction effects were observed for rs7394871, rs174602, rs174570, rs7482316 and rs482548 (p = 0.03, p = 0.01, p = 0.03, p = 0.05 and p = 0.07; respectively). Conclusion: Results suggest that SNPs in the FADS gene cluster may modulate plasma FG, FI and HOMA-IS levels in response to n-3 PUFA supplementation. PMID:24705214

  11. Polymorphisms in Fatty Acid Desaturase (FADS) Gene Cluster: Effects on Glycemic Controls Following an Omega-3 Polyunsaturated Fatty Acids (PUFA) Supplementation.

    PubMed

    Cormier, Hubert; Rudkowska, Iwona; Thifault, Elisabeth; Lemieux, Simone; Couture, Patrick; Vohl, Marie-Claude

    2013-09-10

    Changes in desaturase activity are associated with insulin sensitivity and may be associated with type 2 diabetes mellitus (T2DM). Polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster have been associated with the homeostasis model assessment of insulin sensitivity (HOMA-IS) and serum fatty acid composition. To investigate whether common genetic variations in the FADS gene cluster influence fasting glucose (FG) and fasting insulin (FI) responses following a 6-week n-3 polyunsaturated fatty acids (PUFA) supplementation. 210 subjects completed a 2-week run-in period followed by a 6-week supplementation with 5 g/d of fish oil (providing 1.9 g-2.2 g of EPA + 1.1 g of DHA). Genotyping of 18 SNPs of the FADS gene cluster covering 90% of all common genetic variations (minor allele frequency ≥ 0.03) was performed. Carriers of the minor allele for rs482548 (FADS2) had increased plasma FG levels after the n-3 PUFA supplementation in a model adjusted for FG levels at baseline, age, sex, and BMI. A significant genotype*supplementation interaction effect on FG levels was observed for rs482548 (p = 0.008). For FI levels, a genotype effect was observed with one SNP (rs174456). For HOMA-IS, several genotype*supplementation interaction effects were observed for rs7394871, rs174602, rs174570, rs7482316 and rs482548 (p = 0.03, p = 0.01, p = 0.03, p = 0.05 and p = 0.07; respectively). RESULTS suggest that SNPs in the FADS gene cluster may modulate plasma FG, FI and HOMA-IS levels in response to n-3 PUFA supplementation.

  12. Cardiometabolic risk factors are influenced by Stearoyl-CoA Desaturase (SCD) -1 gene polymorphisms and n-3 polyunsaturated fatty acid supplementation.

    PubMed

    Rudkowska, Iwona; Julien, Pierre; Couture, Patrick; Lemieux, Simone; Tchernof, André; Barbier, Olivier; Vohl, Marie-Claude

    2014-05-01

    To determine if single nucleotide polymorphisms (SNPs) in stearoyl-CoA desaturase (SCD)-1 gene that encodes a key enzyme for fatty acid metabolism are associated with the response of cardiometabolic risk factors to n-3 PUFA supplementation. Two hundred and ten subjects completed a 2-week run-in period followed by 6-week supplementation with 5 g of fish oil (1.9-2.2 g eicosapentaenoic acid and 1.1 g docosahexaenoic acid). Risk factors were measured pre and post n-3 supplementation. Fatty acid composition of plasma phospholipids was analyzed by GC and the desaturase indices SCD16 (16:1n-7/16:0) and SCD18 (18:1n-9/18:0) were calculated. Genotyping of eight SNPs of the SCD1 gene was performed. N-3 PUFA supplementation decreased plasma triglycerides, as well as SCD16 and SCD18 indices, but increased fasting plasma glucose concentrations. SNPs in SCD1-modified cardiometabolic risk factors pre and post n-3 PUFA supplementation: triglyceride (rs508384, p = 0.0086), IL6 (rs3071, p = 0.0485), C-reactive protein (rs3829160, p = 0.0489), and SCD18 indices (rs2234970, p = 0.0337). A significant interaction effect between the SNP and n-3 PUFA supplementation was also observed for fasting plasma glucose levels (rs508384, p = 0.0262). These results suggest that cardiometabolic risk factors are modulated by genetic variations in the SCD1 gene alone or in combination with n-3 PUFA supplementation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Determination of fatty acid composition in seed oil of rapeseed (Brassica napus L.) by mutated alleles of the FAD3 desaturase genes.

    PubMed

    Bocianowski, Jan; Mikołajczyk, Katarzyna; Bartkowiak-Broda, Iwona

    2012-02-01

    One of the goals in oilseed rape programs is to develop genotypes producing oil with low linolenic acid content (C18:3, ≤3%). Low linolenic mutant lines of canola rapeseed were obtained via chemical mutagenesis at the Plant Breeding and Acclimatization Institute - NRI, in Poznan, Poland, and allele-specific SNP markers were designed for monitoring of two statistically important single nucleotide polymorphisms detected by SNaPshot analysis in two FAD3 desaturase genes, BnaA.FAD3 and BnaC.FAD3, respectively. Strong negative correlation between the presence of mutant alleles of the genes and linolenic acid content was revealed by analysis of variance. In this paper we present detailed characteristics of the markers by estimation of the additive and dominance effects of the FAD3 genes with respect to particular fatty acid content in seed oil, as well as by calculation of the phenotypic variation of seed oil fatty acid composition accounted by particular allele-specific marker. The obtained percentage of variation in fatty acid composition was considerable only for linolenic acid content and equaled 35.6% for BnaA.FAD3 and 39.3% for BnaC.FAD3, whereas the total percentage of variation in linolenic acid content was 53.2% when accounted for mutations in both genes simultaneously. Our results revealed high specificity of the markers for effective monitoring of the wild-type and mutated alleles of the Brassica napus FAD3 desaturase genes in the low linolenic mutant recombinants in breeding programs.

  14. Stacking of a stearoyl-ACP thioesterase with a dual-silenced palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase in transgenic soybean.

    PubMed

    Park, Hyunwoo; Graef, George; Xu, Yixiang; Tenopir, Patrick; Clemente, Tom E

    2014-10-01

    Soybean (Glycine max (L.) Merr) is valued for both its protein and oil, whose seed is composed of 40% and 20% of each component, respectively. Given its high percentage of polyunsaturated fatty acids, linoleic acid and linolenic acid, soybean oil oxidative stability is relatively poor. Historically food processors have employed a partial hydrogenation process to soybean oil as a means to improve both the oxidative stability and functionality in end-use applications. However, the hydrogenation process leads to the formation of trans-fats, which are associated with negative cardiovascular health. As a means to circumvent the need for the hydrogenation process, genetic approaches are being pursued to improve oil quality in oilseeds. In this regard, we report here on the introduction of the mangosteen (Garcinia mangostana) stearoyl-ACP thioesterase into soybean and the subsequent stacking with an event that is dual-silenced in palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase expression in a seed-specific fashion. Phenotypic analyses on transgenic soybean expressing the mangosteen stearoyl-ACP thioesterase revealed increases in seed stearic acid levels up to 17%. The subsequent stacked with a soybean event silenced in both palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase activity, resulted in a seed lipid phenotype of approximately 11%-19% stearate and approximately 70% oleate. The oil profile created by the stack was maintained for four generations under greenhouse conditions and a fifth generation under a field environment. However, in generation six and seven under field conditions, the oleate levels decreased to 30%-40%, while the stearic level remained elevated. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  15. Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.

    PubMed Central

    Lindqvist, Y; Huang, W; Schneider, G; Shanklin, J

    1996-01-01

    The three-dimensional structure of recombinant homodimeric delta9 stearoyl-acyl carrier protein desaturase, the archetype of the soluble plant fatty acid desaturases that convert saturated to unsaturated fatty acids, has been determined by protein crystallographic methods to a resolution of 2.4 angstroms. The structure was solved by a combination of single isomorphous replacement, anomalous contribution from the iron atoms to the native diffraction data and 6-fold non-crystallographic symmetry averaging. The 363 amino acid monomer consists of a single domain of 11 alpha-helices. Nine of these form an antiparallel helix bundle. The enzyme subunit contains a di-iron centre, with ligands from four of the alpha-helices in the helix bundle. The iron ions are bound in a highly symmetric environment, with one of the irons forming interactions with the side chains of E196 and H232 and the second iron with the side chains of E105 and H146. Two additional glutamic acid side chains, from E143 and E229, are within coordination distance to both iron ions. A water molecule is found within the second coordination sphere from the iron atoms. The lack of electron density corresponding to a mu-oxo bridge, and the long (4.2 angstroms) distance between the iron ions suggests that this probably represents the diferrous form of the enzyme. A deep channel which probably binds the fatty acid extends from the surface into the interior of the enzyme. Modelling of the substrate, stearic acid, into this channel places the delta9 carbon atom in the vicinity of one of the iron ions. Images PMID:8861937

  16. Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins.

    PubMed

    Lindqvist, Y; Huang, W; Schneider, G; Shanklin, J

    1996-08-15

    The three-dimensional structure of recombinant homodimeric delta9 stearoyl-acyl carrier protein desaturase, the archetype of the soluble plant fatty acid desaturases that convert saturated to unsaturated fatty acids, has been determined by protein crystallographic methods to a resolution of 2.4 angstroms. The structure was solved by a combination of single isomorphous replacement, anomalous contribution from the iron atoms to the native diffraction data and 6-fold non-crystallographic symmetry averaging. The 363 amino acid monomer consists of a single domain of 11 alpha-helices. Nine of these form an antiparallel helix bundle. The enzyme subunit contains a di-iron centre, with ligands from four of the alpha-helices in the helix bundle. The iron ions are bound in a highly symmetric environment, with one of the irons forming interactions with the side chains of E196 and H232 and the second iron with the side chains of E105 and H146. Two additional glutamic acid side chains, from E143 and E229, are within coordination distance to both iron ions. A water molecule is found within the second coordination sphere from the iron atoms. The lack of electron density corresponding to a mu-oxo bridge, and the long (4.2 angstroms) distance between the iron ions suggests that this probably represents the diferrous form of the enzyme. A deep channel which probably binds the fatty acid extends from the surface into the interior of the enzyme. Modelling of the substrate, stearic acid, into this channel places the delta9 carbon atom in the vicinity of one of the iron ions.

  17. Loss of Function of FATTY ACID DESATURASE7 in Tomato Enhances Basal Aphid Resistance in a Salicylate-Dependent Manner1[W][OA

    PubMed Central

    Avila, Carlos A.; Arévalo-Soliz, Lirio M.; Jia, Lingling; Navarre, Duroy A.; Chen, Zhaorigetu; Howe, Gregg A.; Meng, Qing-Wei; Smith, Jonathon E.; Goggin, Fiona L.

    2012-01-01

    We report here that disruption of function of the ω-3 FATTY ACID DESATURASE7 (FAD7) enhances plant defenses against aphids. The suppressor of prosystemin-mediated responses2 (spr2) mutation in tomato (Solanum lycopersicum), which eliminates the function of FAD7, reduces the settling behavior, survival, and fecundity of the potato aphid (Macrosiphum euphorbiae). Likewise, the antisense suppression of LeFAD7 expression in wild-type tomato plants reduces aphid infestations. Aphid resistance in the spr2 mutant is associated with enhanced levels of salicylic acid (SA) and mRNA encoding the pathogenesis-related protein P4. Introduction of the Naphthalene/salicylate hydroxylase transgene, which suppresses SA accumulation, restores wild-type levels of aphid susceptibility to spr2. Resistance in spr2 is also lost when we utilize virus-induced gene silencing to suppress the expression of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1), a positive regulator of many SA-dependent defenses. These results indicate that FAD7 suppresses defenses against aphids that are mediated through SA and NPR1. Although loss of function of FAD7 also inhibits the synthesis of jasmonate (JA), the effects of this desaturase on aphid resistance are not dependent on JA; other mutants impaired in JA synthesis (acx1) or perception (jai1-1) show wild-type levels of aphid susceptibility, and spr2 retains aphid resistance when treated with methyl jasmonate. Thus, FAD7 may influence JA-dependent defenses against chewing insects and SA-dependent defenses against aphids through independent effects on JA synthesis and SA signaling. The Arabidopsis (Arabidopsis thaliana) mutants Atfad7-2 and Atfad7-1fad8 also show enhanced resistance to the green peach aphid (Myzus persicae) compared with wild-type controls, indicating that FAD7 influences plant-aphid interactions in at least two plant families. PMID:22291202

  18. Affects and Affect Consciousness

    PubMed Central

    MONSEN, JON T.; EILERTSEN, DAG ERIK; MELGÅRD, TROND; ØDEGÅRD, PÅL

    1996-01-01

    Affect consciousness (AC) was operationalized as degrees of awareness, tolerance, nonverbal expression, and conceptual expression of nine specific affects. A semistructured interview (ACI) and separate scales were developed to assess these aspects of affect integration. Their psychometric properties were preliminarily explored by having 20 former psychiatric outpatients complete the interview. Concurrent validity was assessed by using DSM-III-R Axis I and II diagnoses, the Health-Sickness Rating Scale, SCL-90-R, and several indexes from the Minnesota Multiphasic Personality Inventory. Satisfactory interrater reliability and high levels of internal consistency supported the construct validity of the measure. Results suggest the most meaningful use of this instrument is in measuring specific affect and overall AC. Clinically, the ACI has provided highly specific and relevant qualitative data for use in planning psychotherapeutic interventions. PMID:22700292

  19. Testosterone differentially regulates targets of lipid and glucose metabolism in liver, muscle and adipose tissues of the testicular feminised mouse.

    PubMed

    Kelly, Daniel M; Akhtar, Samia; Sellers, Donna J; Muraleedharan, Vakkat; Channer, Kevin S; Jones, T Hugh

    2016-11-01

    Testosterone deficiency is commonly associated with obesity, metabolic syndrome, type 2 diabetes and their clinical consequences-hepatic steatosis and atherosclerosis. The testicular feminised mouse (non-functional androgen receptor and low testosterone) develops fatty liver and aortic lipid streaks on a high-fat diet, whereas androgen-replete XY littermate controls do not. Testosterone treatment ameliorates these effects, although the underlying mechanisms remain unknown. We compared the influence of testosterone on the expression of regulatory targets of glucose, cholesterol and lipid metabolism in muscle, liver, abdominal subcutaneous and visceral adipose tissue. Testicular feminised mice displayed significantly reduced GLUT4 in muscle and glycolytic enzymes in muscle, liver and abdominal subcutaneous but not visceral adipose tissue. Lipoprotein lipase required for fatty acid uptake was only reduced in subcutaneous adipose tissue; enzymes of fatty acid synthesis were increased in liver and subcutaneous tissue. Stearoyl-CoA desaturase-1 that catalyses oleic acid synthesis and is associated with insulin resistance was increased in visceral adipose tissue and cholesterol efflux components (ABCA1, apoE) were decreased in subcutaneous and liver tissue. Master regulator nuclear receptors involved in metabolism-Liver X receptor expression was suppressed in all tissues except visceral adipose tissue, whereas PPARγ was lower in abdominal subcutaneous and visceral adipose tissue and PPARα only in abdominal subcutaneous. Testosterone treatment improved the expression (androgen receptor independent) of some targets but not all. These exploratory data suggest that androgen deficiency may reduce the buffering capability for glucose uptake and utilisation in abdominal subcutaneous and muscle and fatty acids in abdominal subcutaneous. This would lead to an overspill and uptake of excess glucose and triglycerides into visceral adipose tissue, liver and arterial walls.

  20. Non-alcoholic fatty liver disease, to struggle with the strangle: Oxygen availability in fatty livers.

    PubMed

    Anavi, Sarit; Madar, Zecharia; Tirosh, Oren

    2017-10-01

    Nonalcoholic fatty liver diseases (NAFLD) is one of the most common chronic liver disease in Western countries. Oxygen is a central component of the cellular microenvironment, which participate in the regulation of cell survival, differentiation, functions and energy metabolism. Accordingly, sufficient oxygen supply is an important factor for tissue durability, mainly in highly metabolic tissues, such as the liver. Accumulating evidence from the past few decades provides strong support for the existence of interruptions in oxygen availability in fatty livers. This outcome may be the consequence of both, impaired systemic microcirculation and cellular membrane modifications which occur under steatotic conditions. This review summarizes current knowledge regarding the main factors which can affect oxygen supply in fatty liver. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Recurrent hepatitis C after liver transplant

    PubMed Central

    deLemos, Andrew S; Schmeltzer, Paul A; Russo, Mark W

    2014-01-01

    End stage liver disease from hepatitis C is the most common indication for liver transplantation in many parts of the world accounting for up to 40% of liver transplants. Antiviral therapy either before or after liver transplantation is challenging due to side effects and lower efficacy in patients with cirrhosis and liver transplant recipients, as well as from drug interactions with immunosuppressants. Factors that may affect recurrent hepatitis C include donor age, immunosuppression, IL28B genotype, cytomegalovirus infection, and metabolic syndrome. Older donor age has persistently been shown to have the greatest impact on recurrent hepatitis C. After liver transplantation, distinguishing recurrent hepatitis C from acute cellular rejection may be difficult, although the development of molecular markers may help in making the correct diagnosis. The advent of interferon free regimens with direct acting antiviral agents that include NS3/4A protease inhibitors, NS5B polymerase inhibitors and NS5A inhibitors holds great promise in improving outcomes for liver transplant candidates and recipients. PMID:25152571

  2. Hyaluronic acid concentration in liver diseases.

    PubMed

    Gudowska, Monika; Gruszewska, Ewa; Panasiuk, Anatol; Cylwik, Bogdan; Flisiak, Robert; Świderska, Magdalena; Szmitkowski, Maciej; Chrostek, Lech

    2016-11-01

    The aim of this study was to evaluate the effect of liver diseases of different etiologies and clinical severity of liver cirrhosis on the serum level of hyaluronic acid. The results were compared with noninvasive markers of liver fibrosis: APRI, GAPRI, HAPRI, FIB-4 and Forn's index. Serum samples were obtained from 20 healthy volunteers and patients suffering from alcoholic cirrhosis (AC)-57 patients, non-alcoholic cirrhosis (NAC)-30 and toxic hepatitis (HT)-22. Cirrhotic patients were classified according to Child-Pugh score. Hyaluronic acid concentration was measured by the immunochemical method. Non-patented indicators were calculated using special formulas. The mean serum hyaluronic acid concentration was significantly higher in AC, NAC and HT group in comparison with the control group. There were significant differences in the serum hyaluronic acid levels between liver diseases, and in AC they were significantly higher than those in NAC and HT group. The serum hyaluronic acid level differs significantly due to the severity of cirrhosis and was the highest in Child-Pugh class C. The sensitivity, specificity, accuracy, positive and negative predictive values and the area under the ROC curve for hyaluronic acid and all non-patented algorithms were high and similar to each other. We conclude that the concentration of hyaluronic acid changes in liver diseases and is affected by the severity of liver cirrhosis. Serum hyaluronic acid should be considered as a good marker for noninvasive diagnosis of liver damage, but the combination of markers is more useful.

  3. Early postnatal feed restriction reduces liver connective tissue levels and affects H3K9 acetylation state of regulated genes associated with protein metabolism in low birth weight pigs.

    PubMed

    Nebendahl, Constance; Görs, Solvig; Albrecht, Elke; Krüger, Ricarda; Martens, Karen; Giller, Katrin; Hammon, Harald M; Rimbach, Gerald; Metges, Cornelia C

    2016-03-01

    Intrauterine growth retardation is associated with metabolic consequences in adulthood. Since our previous data indicate birth weight-dependent effects of feed restriction (R) on protein degradation processes in the liver, it should be investigated whether effects on connective tissue turnover are obvious and could be explained by global changes of histone H3K9me3 and H3K9ac states in regulated genes. For this purpose, female littermate pigs with low (U) or normal (N) birth weight were subjected to 3-week R (60% of ad libitum fed controls) with subsequent refeeding (REF) for further 5 weeks. The 3-week R-period induced a significant reduction of connective tissue area by 43% in the liver of U animals at 98 d of age, which was not found in age-matched N animals. Of note, after REF at 131 d of age, in previously feed-restricted U animals (UR), the percentage of mean connective tissue was only 53% of ad libitum fed controls (UK), indicating a persistent effect. In U animals, R induced H3K9 acetylation of regulated genes (e.g. XBP1, ERLEC1, GALNT2, PTRH2), which were inter alia associated with protein metabolism. In contrast, REF was mostly accompanied by deacetylation in U and N animals. Thus, our epigenetic data may give a first explanation for the observed birth weight-dependent differences in this connective tissue phenotype. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Trichloroethylene: Metabolism and Other Biological Determinants of Mouse Liver Tumors

    DTIC Science & Technology

    1994-09-01

    mineral oil, corn oil, and Tween-80 vehicle. The vehicle in which the chemical was administered affected the magnitude of liver injury in fasted rats...With mineral oil or corn oil, injury was massive, whereas with aqueous Tween-80 vehicle, injury was moderate. In contrast, liver injury in all fed...605. Comporti, M. 1985. Lipid peroxidation and cellular damage in toxic liver injury . Lab Invest. 53:599-623. Conway, J.G., K.E. Tomaszewski, K.E

  5. [Liver and sport].

    PubMed

    Watelet, J

    2008-11-01

    The liver is a vital organ and plays a central role in energy exchange, protein synthesis as well as the elimination of waste products from the body. Acute and chronic injury may disturb a variety of liver functions to different degrees. Over the last three decades, the effects of physical activity and competitive sport on the liver have been described by various investigators. These include viral hepatitis and drug-induced liver disorders. Herein, we review acute and chronic liver diseases potentially caused by sport. Team physicians, trainers and others, responsible for the health of athletes, should be familiar with the risk factors, clinical features, and consequences of liver diseases that occur in sports.

  6. Orchestrating liver development.

    PubMed

    Gordillo, Miriam; Evans, Todd; Gouon-Evans, Valerie

    2015-06-15

    The liver is a central regulator of metabolism, and liver failure thus constitutes a major health burden. Understanding how this complex organ develops during embryogenesis will yield insights into how liver regeneration can be promoted and how functional liver replacement tissue can be engineered. Recent studies of animal models have identified key signaling pathways and complex tissue interactions that progressively generate liver progenitor cells, differentiated lineages and functional tissues. In addition, progress in understanding how these cells interact, and how transcriptional and signaling programs precisely coordinate liver development, has begun to elucidate the molecular mechanisms underlying this complexity. Here, we review the lineage relationships, signaling pathways and transcriptional programs that orchestrate hepatogenesis. © 2015. Published by The Company of Biologists Ltd.

  7. Fatty acid composition and development of hepatic lipidosis during food deprivation--mustelids as a potential animal model for liver steatosis.

    PubMed

    Nieminen, Petteri; Mustonen, Anne-Mari; Kärjä, Vesa; Asikainen, Juha; Rouvinen-Watt, Kirsti

    2009-03-01

    Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome characterized by asymptomatic hepatic steatosis. It is present in most cases of human obesity but also caused e.g., by rapid weight loss. The patients have decreased n-3 polyunsaturated fatty acid (PUFA) proportions with decreased percentages of 18:3(n-3), 20:5(n-3) and 22:6(n-3) and an increased n-6/n-3 PUFA ratio in liver and/or white adipose tissue (WAT). The present study examined a new experimental model to study liver steatosis with possible future applications to NAFLD. Ten European polecats (Mustela putorius), the wild form of the domestic ferret, were food-deprived for 5 days with 10 fed animals as controls. The food-deprived animals showed micro- and macrovesicular hepatic steatosis, decreased proportions of 20:5(n-3), 22:6(n-3) and total n-3 PUFA and increased n-6/n-3 PUFA ratios in liver and WAT. At the same time, the product/precursor ratios decreased in liver. The observed effects can be due to selective fatty acid mobilization preferring n-3 PUFA over n-6 PUFA, decreased Delta5 and Delta6 desaturase activities, oxidative stress, decreased arginine availability and activation of the endocannabinoid system. Hepatic lipidosis induced by food deprivation was manifested in the fatty acid composition of the polecat with similarities to human NAFLD despite the different principal etiologies.

  8. Acute liver failure.

    PubMed

    Slack, Andy; Wendon, Julia

    2011-06-01

    ALF is a multisystem disorder necessitating both predictive and reactive management strategies to support and protect organs from the initial and subsequent insults encountered. Early referral to a specialist liver centre with the option of liver transplantation is recommended. Furthermore, a good understanding of the poor prognostic variables is necessary to determine those most at risk of developing ALF in order to facilitate timely, safe transfer and listing for liver transplantation.

  9. Robotic liver surgery

    PubMed Central

    Leung, Universe

    2014-01-01

    Robotic surgery is an evolving technology that has been successfully applied to a number of surgical specialties, but its use in liver surgery has so far been limited. In this review article we discuss the challenges of minimally invasive liver surgery, the pros and cons of robotics, the evolution of medical robots, and the potentials in applying this technology to liver surgery. The current data in the literature are also presented. PMID:25392840

  10. Diagnosis and Management of Alcoholic Liver Disease.

    PubMed

    Dugum, Mohannad; McCullough, Arthur

    2015-06-28

    Alcohol is a leading cause of liver disease and is associated with significant morbidity and mortality. Several factors, including the amount and duration of alcohol consumption, affect the development and progression of alcoholic liver disease (ALD). ALD represents a spectrum of liver pathology ranging from fatty change to fibrosis to cirrhosis. Early diagnosis of ALD is important to encourage alcohol abstinence, minimize the progression of liver fibrosis, and manage cirrhosis-related complications including hepatocellular carcinoma. A number of questionnaires and laboratory tests are available to screen for alcohol intake. Liver biopsy remains the gold-standard diagnostic tool for ALD, but noninvasive accurate alternatives, including a number of biochemical tests as well as liver stiffness measurement, are increasingly being utilized in the evaluation of patients with suspected ALD. The management of ALD depends largely on complete abstinence from alcohol. Supportive care should focus on treating alcohol withdrawal and providing enteral nutrition while managing the complications of liver failure. Alcoholic hepatitis (AH) is a devastating acute form of ALD that requires early recognition and specialized tertiary medical care. Assessment of AH severity using defined scoring systems is important to allocate resources and initiate appropriate therapy. Corticosteroids or pentoxifylline are commonly used in treating AH but provide a limited survival benefit. Liver transplantation represents the ultimate therapy for patients with alcoholic cirrhosis, with most transplant centers mandating a 6 month period of abstinence from alcohol before listing. Early liver transplantation is also emerging as a therapeutic measure in specifically selected patients with severe AH. A number of novel targeted therapies for ALD are currently being evaluated in clinical trials.

  11. Autoimune liver disease panel

    MedlinePlus

    ... liver cirrhosis or chronic active hepatitis. Risks Slight risks from having blood drawn include: Excessive bleeding Fainting or feeling lightheaded Hematoma (blood accumulating under the skin) Infection ( ...

  12. ω-3 Fatty acids reverse lipotoxity through induction of autophagy in nonalcoholic fatty liver disease.

    PubMed

    Chen, Yi; Xu, Chengfu; Yan, Tianlian; Yu, Chaohui; Li, Youming

    2015-01-01

    The aim of this study was to evaluate the effect of ω-3 fatty acids on nonalcoholic fatty liver disease concerning hepatocyte lipid accumulation as well as apoptosis induced by free fatty acids (FFAs) and to explore the underlying mechanism involving autophagy. Hepatocytes were incubated with a mixture of free fatty acids (FFAs) to mimic in vitro lipotoxicity in the pathogenesis of nonalcoholic fatty liver disease, presented by lipid accumulation and cellular apoptosis. Chemical inhibitor or inducer of autophagy and genetic deficit cells, as well as ω-3 fatty acids were used as intervention. The autophagic role of ω-3 fatty acids was investigated using Western blot and immunofluorescence. The underlying mechanism of ω-3 fatty acids involving autophagy was preliminarily explored by quantitative real-time polymerase chain reaction and Western blot. FFAs induce lipid accumulation and apoptosis in hepatocytes. Inhibition or genetic defect of autophagy increases lipid accumulation induced by FFA, whereas induction acts inversely. ω-3 Fatty acids reduced lipid accumulation and inhibited apoptosis induced by FFA. ω-3 Fatty acids induced autophagy by downregulating stearoyl-CoA desaturase 1 expression in hepatocytes. ω-3 Fatty acids exert protective effects on hepatocytes against lipotoxicity through induction of autophagy, as demonstrated by inhibition of lipid accumulation and apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Effects of Natural Products on Fructose-Induced Nonalcoholic Fatty Liver Disease (NAFLD).

    PubMed

    Chen, Qian; Wang, Tingting; Li, Jian; Wang, Sijian; Qiu, Feng; Yu, Haiyang; Zhang, Yi; Wang, Tao

    2017-01-31

    As a sugar additive, fructose is widely used in processed foods and beverages. Excessive fructose consumption can cause hepatic steatosis and dyslipidemia, leading to the development of metabolic syndrome. Recent research revealed that fructose-induced nonalcoholic fatty liver disease (NAFLD) is related to several pathological processes, including: (1) augmenting lipogenesis; (2) leading to mitochondrial dysfunction; (3) stimulating the activation of inflammatory pathways; and (4) causing insulin resistance. Cellular signaling research indicated that partial factors play significant roles in fructose-induced NAFLD, involving liver X receptor (LXR)α, sterol regulatory element binding protein (SREBP)-1/1c, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), peroxisome proliferator-activated receptor α (PPARα), leptin nuclear factor-erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-κB), tumor necrosis factor α (TNF-α), c-Jun amino terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Until now, a series of natural products have been reported as regulators of NAFLD in vivo and in vitro. This paper reviews the natural products (e.g., curcumin, resveratrol, and (-)-epicatechin) and their mechanisms of ameliorating fructose-induced NAFLD over the past years. Although, as lead compounds, natural products usually have fewer activities compared with synthesized compounds, it will shed light on studies aiming to discover new drugs for NAFLD.

  14. Probabilistic liver atlas construction.

    PubMed

    Dura, Esther; Domingo, Juan; Ayala, Guillermo; Marti-Bonmati, Luis; Goceri, E

    2017-01-13

    Anatomical atlases are 3D volumes or shapes representing an organ or structure of the human body. They contain either the prototypical shape of the object of interest together with other shapes representing its statistical variations (statistical atlas) or a probability map of belonging to the object (probabilistic atlas). Probabilistic atlases are mostly built with simple estimations only involving the data at each spatial location. A new method for probabilistic atlas construction that uses a generalized linear model is proposed. This method aims to improve the estimation of the probability to be covered by the liver. Furthermore, all methods to build an atlas involve previous coregistration of the sample of shapes available. The influence of the geometrical transformation adopted for registration in the quality of the final atlas has not been sufficiently investigated. The ability of an atlas to adapt to a new case is one of the most important quality criteria that should be taken into account. The presented experiments show that some methods for atlas construction are severely affected by the previous coregistration step. We show the good performance of the new approach. Furthermore, results suggest that extremely flexible registration methods are not always beneficial, since they can reduce the variability of the atlas and hence its ability to give sensible values of probability when used as an aid in segmentation of new cases.

  15. Circulating lipocalin 2 is neither related to liver steatosis in patients with non-alcoholic fatty liver disease nor to residual liver function in cirrhosis.

    PubMed

    Meier, Elisabeth M; Pohl, Rebekka; Rein-Fischboeck, Lisa; Schacherer, Doris; Eisinger, Kristina; Wiest, Reiner; Krautbauer, Sabrina; Buechler, Christa

    2016-09-01

    Lipocalin 2 (LCN2) is induced in the injured liver and associated with inflammation. Aim of the present study was to evaluate whether serum LCN2 is a non-invasive marker to assess hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD) or residual liver function in patients with liver cirrhosis. Therefore, LCN2 was measured by ELISA in serum of 32 randomly selected patients without fatty liver (controls), 24 patients with ultrasound diagnosed NAFLD and 42 patients with liver cirrhosis mainly due to alcohol. Systemic LCN2 was comparable in patients with liver steatosis, those with liver cirrhosis and controls. LCN2 negatively correlated with bilirubin in both cohorts. In cirrhosis, LCN2 was not associated with more advanced liver injury defined by the CHILD-PUGH score and model for end-stage liver disease score. Resistin but not C-reactive protein or chemerin positively correlated with LCN2. LCN2 levels were not increased in patients with ascites or patients with esophageal varices. Consequently, reduction of portal pressure by transjugular intrahepatic portosystemic shunt did not affect LCN2 levels. Hepatic venous blood (HVS), portal venous blood and systemic venous blood levels of LCN2 were similar. HVS LCN2 was unchanged in patients with end-stage liver cirrhosis compared to those with well-compensated disease arguing against increased hepatic release. Current data exclude that serum LCN2 is of any value as steatosis marker in patients with NAFLD and indicator of liver function in patients with alcoholic liver cirrhosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Transcriptional Activation of Two Delta-9 Palmitoyl-ACP Desaturase Genes by MYB115 and MYB118 Is Critical for Biosynthesis of Omega-7 Monounsaturated Fatty Acids in the Endosperm of Arabidopsis Seeds

    PubMed Central

    Troncoso-Ponce, Manuel Adrián; Barthole, Guillaume; Tremblais, Geoffrey

    2016-01-01

    In angiosperms, double fertilization of the embryo sac initiates the development of the embryo and the endosperm. In Arabidopsis thaliana, an exalbuminous species, the endosperm is reduced to one cell layer during seed maturation and reserves such as oil are massively deposited in the enlarging embryo. Here, we consider the strikingly different fatty acid (FA) compositions of the oils stored in the two zygotic tissues. Endosperm oil is enriched in ω-7 monounsaturated FAs, that represent more than 20 mol% of total FAs, whereas these molecular species are 10-fold less abundant in the embryo. Two closely related transcription factors, MYB118 and MYB115, are transcriptionally induced at the onset of the maturation phase in the endosperm and share a set of transcriptional targets. Interestingly, the endosperm oil of myb115 myb118 double mutants lacks ω-7 FAs. The identification of two Δ9 palmitoyl-ACP desaturases responsible for ω-7 FA biosynthesis, which are activated by MYB115 and MYB118 in the endosperm, allows us to propose a model for the transcriptional control of oil FA composition in this tissue. In addition, an initial characterization of the structure-function relationship for these desaturases reveals that their particular substrate specificity is conferred by amino acid residues lining their substrate pocket that distinguish them from the archetype Δ9 stearoyl-ACP desaturase. PMID:27681170

  17. EFFECTS OF X IRRADIATION ON ENZYME SYNTHESIS DURING LIVER REGENERATION

    SciTech Connect

    Myers, D.K.

    1962-05-01

    Twenty-four different enzymes or enzyme systems were assayed in regenerating rat liver from control and irradiated animals at various times after partial hepatectomy. X irradiation, either of the whole liver region or of an exteriorized liver lobule, interfered with the accumulation of only three of these enzymes: deoxycytidylate deaminase, thymidine phosphorylase, and NAD pyrophosphorylase. Irradiation did not affect the synthesis of related enzymes such as adenosine and guanine deaminases, and inosine and uridine phosphorylases. The effects of irradiation on enzyme synthesis in regenerating liver would appear to be highly selective. (auth)

  18. MR elastography of the liver at 3.0 T in diagnosing liver fibrosis grades; preliminary clinical experience.

    PubMed

    Yoshimitsu, Kengo; Mitsufuji, Toshimichi; Shinagawa, Yoshinobu; Fujimitsu, Ritsuko; Morita, Ayako; Urakawa, Hiroshi; Hayashi, Hiroyuki; Takano, Koichi

    2016-03-01

    To clarify the usefulness of 3.0-T MR elastography (MRE) in diagnosing the histological grades of liver fibrosis using preliminary clinical data. Between November 2012 and March 2014, MRE was applied to all patients who underwent liver MR study at a 3.0-T clinical unit. Among them, those who had pathological evaluation of liver tissue within 3 months from MR examinations were retrospectively recruited, and the liver stiffness measured by MRE was correlated with histological results. Institutional review board approved this study, waiving informed consent. There were 70 patients who met the inclusion criteria. Liver stiffness showed significant correlation with the pathological grades of liver fibrosis (rho = 0.89, p < 0.0001, Spearman's rank correlation). Areas under the receiver operating characteristic curve were 0.93, 0.95, 0.99 and 0.95 for fibrosis score greater than or equal to F1, F2, F3 and F4, with cut-off values of 3.13, 3.85, 4.28 and 5.38 kPa, respectively. Multivariate analysis suggested that grades of necroinflammation also affected liver stiffness, but to a significantly lesser degree as compared to fibrosis. 3.0-T clinical MRE was suggested to be sufficiently useful in assessing the grades of liver fibrosis. MR elastography may help clinicians assess patients with chronic liver diseases. Usefulness of 3.0-T MR elastography has rarely been reported. Measured liver stiffness correlated well with the histological grades of liver fibrosis. Measured liver stiffness was also affected by necroinflammation, but to a lesser degree. 3.0-T MRE could be a non-invasive alternative to liver biopsy.

  19. Echinococcosis of the Liver

    DTIC Science & Technology

    2007-03-01

    and 1b. The lack of internal enhancement confirms the cystic nature of these lesions. Discussion Echinococcosis , also known as Hydatid disease... Echinococcosis of the Liver Radiology Corner Echinococcosis of the Liver Guarantor...abbreviated answer in the March 2007 issue. 1 Echinococcosis is a parasitic infection that poses a potential health threat to military members and

  20. Cod Liver Oil

    MedlinePlus

    Cod liver oil contains certain "fatty acids" that prevent the blood from clotting easily. These fatty acids also reduce pain and swelling. ... Morue, Huile de Poisson, Liver Oil, N-3 Fatty Acids, Omega 3, Oméga 3, Omega 3 Fatty Acids, ...

  1. Living Donor Liver Transplantation

    MedlinePlus

    ... What are Some Benefits of a Living-donor Liver Transplant? In the U.S., more than 17,500 patients ... 1,700 patients die each year while waiting. Liver transplants are given to patients on the basis of ...

  2. Polyploidization of liver cells.

    PubMed

    Celton-Morizur, Séverine; Desdouets, Chantal

    2010-01-01

    Eukaryotic organisms usually contain a diploid complement of chromosomes. However, there are a number of exceptions. Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago and it is now recognized that polyploidy cells form in many eukaryotes under a wide variety of circumstance. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during postnatal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. This process generates the successive appearance of tetraploid and octoploid cell classes with one or two nuclei (mononucleated or binucleated). Liver cells polyploidy is generally considered to indicate terminal differentiation and senescence and to lead both to the progressive loss of cell pluripotency and a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Interestingly, partial hepatectomy induces marked cell proliferation followed by an increase in liver ploidy. In contrast, during hepatocarcinoma (HCC), growth shifts to a nonpolyploidizing pattern and expansion of the diploid hepatocytes population is observed in neoplastic nodules. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth and detail by which mechanisms hepatocytes become polyploid.

  3. Factors Associated With Short- and Long-term Liver Graft Survival in the United Kingdom: Development of a UK Donor Liver Index.

    PubMed

    Collett, David; Friend, Peter J; Watson, Christopher J E

    2017-04-01

    A measure of donor liver quality, the donor liver index, was developed and validated for the UK population of transplant recipients. Unlike previously proposed measures, this index is only based on variables that are available at the point of retrieval, and so does not include cold ischemic time. Indices of liver quality were based on data from the UK Transplant Registry on all 7929 liver transplants between January 2000 and December 2014. The donor liver index (DLI) was based on factors shown to affect graft survival, which included donor age, sex, height, type (donor after brain death or circulatory death), bilirubin, smoking history, and whether the liver was split. A separate index (DLI1) looking at 1-year survival showed donor cardiac disease, black ethnicity, and steatosis to be additional risk factors. A strong association was found between DLI and whether or not a surgeon accepts an offered liver for transplant, with a marked fall in acceptance rates for livers with an index greater than 1.31. Since 2000, there has been a notable reduction in the quality of livers transplanted, coupled with variation between the 7 UK liver transplant centers in risk appetite. The DLI is an index of liver quality which enables analysis of the changing trends in liver quality and center behavior. DLI1 enables identification of factors affecting shorter-term survival, and perhaps identifies a cohort of livers that may benefit from novel preservation technologies.

  4. [The effect of N-stearoylethanolamine on liver phospholipid composition of rats with insulin resistance caused by alimentary obesity].

    PubMed

    Onopchenko, O V; Kosiakova, H V; Horid'ko, T M; Klimashevskyĭ, V M; Hula, N M

    2014-01-01

    We used alimentary obesity-induced insulin resistance (IR) model in rats to investigate the influence of N-stearoylethanolamine on the content of phospholipids and their fatty acid composition. Our results show that prolonged high-fat diet triggers considerable aberrations in the composition of main phospholipids in the liver and can be one of the causes of IR in rats. In particular, the increase of phosphatidylcholine, phosphatidylethanolamine and significant decrease of other phospholipids: lysophosphatidylcholine, lysophosphatidylethanolamine, sphingomyelin, phosphatidylinositol, phosphatidylserine and diphosphaglicerol were observed. The levels of monounsaturated (erucic, nervonic, oleic) and polyunsaturated (eicosatrienoic, docosatrienoic, arachidonic) fatty acids were increased; meanwhile the content of diunsaturated acids was decreased. The NSE administration (50 mg/kg of body weight) caused restoration of the phospholipids content in the liver of rats with diet-induced IR that highly correlated with the decrease in plasma insulin level and the improvement of insulin sensitivity. Moreover, the effect of NSE was accompanied by the normalization of fatty acids composition of phospholipids that could be related to modulating influence of NSE on the activity of the main fatty acid desaturases. It is known that the imbalance in phospholipid composition of the rat liver causes substantial metabolic alterations that are associated with the development of IR. Accordingly, the compensations of the imbalance by NSE can help to restore insulin sensitivity, inhibit the development of obesity, IR and type 2 diabetes.

  5. Can paracetamol (acetaminophen) be administered to patients with liver impairment?

    PubMed Central

    Hayward, Kelly L.; Powell, Elizabeth E.; Irvine, Katharine M.

    2015-01-01

    Although 60 years have passed since it became widely available on the therapeutic market, paracetamol dosage in patients with liver disease remains a controversial subject. Fulminant hepatic failure has been a well documented consequence of paracetamol overdose since its introduction, while short and long term use have both been associated with elevation of liver transaminases, a surrogate marker for acute liver injury. From these reports it has been assumed that paracetamol use should be restricted or the dosage reduced in patients with chronic liver disease. We review the factors that have been purported to increase risk of hepatocellular injury from paracetamol and the pharmacokinetic alterations in different pathologies of chronic liver disease which may affect this risk. We postulate that inadvertent under‐dosing may result in concentrations too low to enable efficacy. Specific research to improve the evidence base for prescribing paracetamol in patients with different aetiologies of chronic liver disease is needed. PMID:26460177

  6. Can paracetamol (acetaminophen) be administered to patients with liver impairment?

    PubMed

    Hayward, Kelly L; Powell, Elizabeth E; Irvine, Katharine M; Martin, Jennifer H

    2016-02-01

    Although 60 years have passed since it became widely available on the therapeutic market, paracetamol dosage in patients with liver disease remains a controversial subject. Fulminant hepatic failure has been a well documented consequence of paracetamol overdose since its introduction, while short and long term use have both been associated with elevation of liver transaminases, a surrogate marker for acute liver injury. From these reports it has been assumed that paracetamol use should be restricted or the dosage reduced in patients with chronic liver disease. We review the factors that have been purported to increase risk of hepatocellular injury from paracetamol and the pharmacokinetic alterations in different pathologies of chronic liver disease which may affect this risk. We postulate that inadvertent under-dosing may result in concentrations too low to enable efficacy. Specific research to improve the evidence base for prescribing paracetamol in patients with different aetiologies of chronic liver disease is needed. © 2015 The British Pharmacological Society.

  7. Advances in liver transplantation allocation systems.

    PubMed

    Schilsky, Michael L; Moini, Maryam

    2016-03-14

    With the growing number of patients in need of liver transplantation, there is a need for adopting new and modifying existing allocation policies that prioritize patients for liver transplantation. Policy should ensure fair allocation that is reproducible and strongly predictive of best pre and post transplant outcomes while taking into account the natural history of the potential recipients liver disease and its complications. There is wide acceptance for allocation policies based on urgency in which the sickest patients on the waiting list with the highest risk of mortality receive priority. Model for end-stage liver disease and Child-Turcotte-Pugh scoring system, the two most universally applicable systems are used in urgency-based prioritization. However, other factors must be considered to achieve optimal allocation. Factors affecting pre-transplant patient survival and the quality of the donor organ also affect outcome. The optimal system should have allocation prioritization that accounts for both urgency and transplant outcome. We reviewed past and current liver allocation systems with the aim of generating further discussion about improvement of current policies.

  8. Sustained enrichment of liver phospholipids and triglycerides in eicosapentaenoate after a bolus intravenous injection of a medium-chain triglycerides:fish oil emulsion to streptozotocin (Type 1) and Goto-Kakizaki (Type 2) diabetic rats.

    PubMed

    Carpentier, Yvon A; Fontaine, David; Otto, Anne; Portois, Laurence; Fontaine, Jeanine; Malaisse, Willy J

    2006-04-01

    This study deals with the sustained enrichment of liver phospholipids and triglycerides in long-chain polyunsaturated omega3 fatty acids (omega3) found after the bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion (MCT:FO) to streptozotocin (Type 1) and Goto-Kakizaki (Type 2) diabetic rats. Twenty hours after injection of the MCT:FO emulsion, the relative concentration of omega3 was indeed higher in liver phospholipids and triglycerides than that found in rats injected with either saline or a control medium-chain triglyceride:long-chain triglyceride emulsion. This coincided with a decrease in the ponderal percentage of C18:3omega3, C20:4omega6 and/or C22:4omega6 in liver triglycerides. The present study further documents differences between streptozotocin-induced and Goto-Kakizaki diabetic rats in terms of body weight, glycemia, liver triglyceride content and the fatty acid pattern of both liver phospholipids and triglycerides, as well as a close correlation in the latter animals between liver and plasma phospholipids or triglycerides as far as the ratio in the relative concentration of selected fatty acids representative of desaturase and elongase activities is concerned. In light of these and previous findings, it is proposed that the beneficial metabolic and functional events of the MCT:FO emulsion may display not solely a rapid but also sustained time course.

  9. Childhood Liver Cancer Symptoms, Tests, Prognosis, and Stages (PDQ®)—Patient Version

    Cancer.gov

    Liver cancer is rare in children and adolescents. There are two main types of childhood liver cancer. Hepatoblastoma usually affects children 3 years and younger, and hepatocellular carcinoma occurs in older children and teenagers. Learn about risk factors, tests to diagnose, and stages of childhood liver cancer.

  10. Livers from fasted rats acquire resistance to warm and cold ischemia injury.

    PubMed

    Sumimoto, R; Southard, J H; Belzer, F O

    1993-04-01

    Successful liver transplantation is dependent upon many factors, one of which is the quality of the donor organ. Previous studies have suggested that the donor nutritional status may affect the outcome of liver transplantation and starvation, due to prolonged stay in the intensive care unit, may adversely affect the liver. In this study we have used the orthotopic rat liver transplant model to measure how fasting the donor affects the outcome of liver transplantation. Rat livers were preserved with UW solution either at 37 degrees C (warm ischemia for 45-60 min) or at 4 degrees C (cold ischemia for 30 or 44 hr). After preservation the livers were orthotopically transplanted and survival (for 7 days) was measured, as well as liver functions 6 hr after transplantation. After 45 min of warm ischemia 50% (3 of 6) animals survived when the liver was obtained from a fed donor about 80% (4 of 5) survived when the liver was obtained from a three-day-fasted donor. After 60 min warm ischemia no animal survived (0 of 8, fed group). However, if the donor was fasted for 3 days 89% (8 of 9) of the animals survived for 7 days. Livers cold-stored for 30 hr were 50% viable (3 of 6) and fasting for 1-3 days did not affect this outcome. However, if the donor was fasted for 4 days 100% (9 of 9) survival was obtained. After 44-hr preservation only 29% (2/7) of the recipients survived for 7 days. If the donor was fasted for 4 days, survival increased to 83% (5/6). Liver functions, bile production, and serum enzymes were better in livers from the fasted rats than from the fed rats. Fasting caused a 95% decrease in liver glycogen content. Even with this low concentration of glycogen, liver viability (animal survival) after warm or cold ischemia was not affected, and livers with a low glycogen content were fully viable. Thus liver glycogen does not appear to be important in liver preservation. This study shows that fasting the donor does not cause injury to the liver after warm or cold