Relationship between the pentose-phosphate pathway and the de novo synthesis of fatty acids and cholesterol in oligodendrocyte-enriched glial cultures

1986 ◽  
Vol 8 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Jane E.C. Sykes ◽  
Matthijs Lopes-Cardozo ◽  
Simon G. Van Den Bergh
Keyword(s):  
Fatty Acids ◽  
Pentose Phosphate Pathway ◽  
De Novo ◽  
Pentose Phosphate ◽  
De Novo Synthesis ◽  
Glial Cultures

In vivo study of the biosynthesis of long-chain fatty acids using deuterated water

1995 ◽  
Vol 269 (2) ◽  
pp. E247-E252 ◽  
Author(s):  
H. O. Ajie ◽  
M. J. Connor ◽  
W. N. Lee ◽  
S. Bassilian ◽  
E. A. Bergner ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Chain Elongation ◽  
Deuterated Water ◽  
De Novo Synthesis ◽  
Isotopomer Distribution ◽  
Long Chain ◽  
Mass Isotopomer

To determine the contributions of preexisting fatty acid, de novo synthesis, and chain elongation in long-chain fatty acid (LCFA) synthesis, the synthesis of LCFAs, palmitate (16:0), stearate (18:0), arachidate (20:0), behenate (22:0), and lignocerate (24:0), in the epidermis, liver, and spinal cord was determined using deuterated water and mass isotopomer distribution analysis in hairless mice and Sprague-Dawley rats. Animals were given 4% deuterated water for 5 days or 8 wk in their drinking water. Blood was withdrawn at the end of these times for the determination of deuterium enrichment, and the animals were killed to isolate the various tissues for lipid extraction for the determination of the mass isotopomer distributions. The mass isotopomer distributions in LCFA were incompatible with synthesis from a single pool of primer. The synthesis of palmitate, stearate, arachidate, behenate, and lignocerate followed the expected biochemical pathways for the synthesis of LCFAs. On average, three deuterium atoms were incorporated for every addition of an acetyl unit. The isotopomer distribution resulting from chain elongation and de novo synthesis can be described by the linear combination of two binomial distributions. The proportions of preexisting, chain elongation, and de novo-synthesized fatty acids as a percentage of the total fatty acids were determined using multiple linear regression analysis. Fractional synthesis was found to vary, depending on the tissue type and the fatty acid, from 47 to 87%. A substantial fraction (24-40%) of the newly synthesized molecules was derived from chain elongation of unlabeled (recycled) palmitate.

scholarly journals Genome-Wide Metabolic Reconstruction of the Synthesis of Polyhydroxyalkanoates from Sugars and Fatty Acids by Burkholderia Sensu Lato Species

2021 ◽  
Vol 9 (6) ◽  
pp. 1290
Author(s):  
Natalia Alvarez-Santullano ◽  
Pamela Villegas ◽  
Mario Sepúlveda Mardones ◽  
Roberto E. Durán ◽  
Raúl Donoso ◽  
...  
Keyword(s):  
Fatty Acids ◽  
De Novo ◽  
Reducing Power ◽  
Pentose Phosphate ◽  
Fine Tuning ◽  
Metabolic Reconstruction ◽  
Phylogenetic Groups ◽  
Outlier Group ◽  
Pha Genes ◽  
High Level

Burkholderia sensu lato (s.l.) species have a versatile metabolism. The aims of this review are the genomic reconstruction of the metabolic pathways involved in the synthesis of polyhydroxyalkanoates (PHAs) by Burkholderia s.l. genera, and the characterization of the PHA synthases and the pha genes organization. The reports of the PHA synthesis from different substrates by Burkholderia s.l. strains were reviewed. Genome-guided metabolic reconstruction involving the conversion of sugars and fatty acids into PHAs by 37 Burkholderia s.l. species was performed. Sugars are metabolized via the Entner–Doudoroff (ED), pentose-phosphate (PP), and lower Embden–Meyerhoff–Parnas (EMP) pathways, which produce reducing power through NAD(P)H synthesis and PHA precursors. Fatty acid substrates are metabolized via β-oxidation and de novo synthesis of fatty acids into PHAs. The analysis of 194 Burkholderia s.l. genomes revealed that all strains have the phaC, phaA, and phaB genes for PHA synthesis, wherein the phaC gene is generally present in ≥2 copies. PHA synthases were classified into four phylogenetic groups belonging to class I II and III PHA synthases and one outlier group. The reconstruction of PHAs synthesis revealed a high level of gene redundancy probably reflecting complex regulatory layers that provide fine tuning according to diverse substrates and physiological conditions.

The composition and metabolism of fatty acids in Ips paraconfusus Lanier (Coleoptera: Scolytidae)

1972 ◽  
Vol 50 (10) ◽  
pp. 1263-1267 ◽  
Author(s):  
K. R. Penner ◽  
J. S. Barlow
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Sexual Dimorphism ◽  
Acid Composition ◽  
De Novo ◽  
Monounsaturated Fatty Acids ◽  
Ips Paraconfusus ◽  
Chain Elongation ◽  
De Novo Synthesis

The fatty acid composition of newly emerged Ips paraconfusus Lanier shows no sexual dimorphism and is approximately as follows: C14:0, 0.5%; C16:0, 23.0%; C16:1, 6%; C18:0, 3%; C18:1, 55%; C18:2, 9%; C18:3, 2%. Both sexes, but particularly the female, use up fatty acids, particularly the monounsaturated acids, during reproduction. Isotope from 1-14C-acetate injected into newly emerged females appeared in all saturated and monounsaturated fatty acids within 30 min. There was evidence of de novo synthesis of C14:0 and C16:0, chain elongation of C16:0 to C18:0, and desaturation of C16:0 and C18:0 to yield C16:1 and C18:1 respectively.

scholarly journals Unravelling genetic variation underlying de novo-synthesis of bovine milk fatty acids

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tim Martin Knutsen ◽  
Hanne Gro Olsen ◽  
Valeria Tafintseva ◽  
Morten Svendsen ◽  
Achim Kohler ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Genetic Variation ◽  
De Novo ◽  
Bovine Milk ◽  
De Novo Synthesis ◽  
Milk Fatty Acids

scholarly journals The Pentose Phosphate Pathway and Pyruvate Carboxylation after Neonatal Hypoxic-Ischemic Brain Injury

2014 ◽  
Vol 34 (4) ◽  
pp. 724-734 ◽  
Author(s):  
Eva MF Brekke ◽  
Tora S Morken ◽  
Marius Widerøe ◽  
Asta K Håberg ◽  
Ann-Mari Brubakk ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glucose Metabolism ◽  
Pentose Phosphate Pathway ◽  
De Novo ◽  
Pentose Phosphate ◽  
Adult Brain ◽  
Resonance Spectroscopy ◽  
Neonatal Brain ◽  
Artery Ligation ◽  
Pyruvate Carboxylation

The neonatal brain is vulnerable to oxidative stress, and the pentose phosphate pathway (PPP) may be of particular importance to limit the injury. Furthermore, in the neonatal brain, neurons depend on de novo synthesis of neurotransmitters via pyruvate carboxylase (PC) in astrocytes to increase neurotransmitter pools. In the adult brain, PPP activity increases in response to various injuries while pyruvate carboxylation is reduced after ischemia. However, little is known about the response of these pathways after neonatal hypoxia-ischemia (HI). To this end, 7-day-old rats were subjected to unilateral carotid artery ligation followed by hypoxia. Animals were injected with [1,2-13C]glucose during the recovery phase and extracts of cerebral hemispheres ipsi- and contralateral to the operation were analyzed using 1H- and 13C-NMR (nuclear magnetic resonance) spectroscopy and high-performance liquid chromatography (HPLC). After HI, glucose levels were increased and there was evidence of mitochondrial hypometabolism in both hemispheres. Moreover, metabolism via PPP was reduced bilaterally. Ipsilateral glucose metabolism via PC was reduced, but PC activity was relatively preserved compared with glucose metabolism via pyruvate dehydrogenase. The observed reduction in PPP activity after HI may contribute to the increased susceptibility of the neonatal brain to oxidative stress.

scholarly journals De novo synthesis of fatty acids is regulated by FapR protein in Exiguobacterium antarcticum B7, a psychrotrophic bacterium isolated from Antarctica

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Rafael A. Baraúna ◽  
Diego A. das Graças ◽  
Catarina I. P. Nunes ◽  
Maria P. C. Schneider ◽  
Artur Silva ◽  
...  
Keyword(s):  
Fatty Acids ◽  
De Novo ◽  
De Novo Synthesis ◽  
Psychrotrophic Bacterium ◽  
Exiguobacterium Antarcticum

Lipid composition of developing Xenopus laevis embryos

1976 ◽  
Vol 54 (6) ◽  
pp. 578-582 ◽  
Author(s):  
Mary Mes-Hartree ◽  
John B. Armstrong
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Xenopus Laevis ◽  
Lipid Content ◽  
Lipid Composition ◽  
De Novo ◽  
Total Lipid Content ◽  
De Novo Synthesis ◽  
Xenopus Laevis Embryos

The total lipid content, amount of phospholipid, proportions of major polar and neutral lipid classes, and the overall fatty acid composition were examined in Xenopus laevis embryos. No obvious differences were observed in any of the parameters between fertilization and hatching, or between eggs produced by different females. The average lipid content per egg was 113 μg, 31.6 μg of which was phospholipid. The major phospholipids were phosphatidylcholine and sphingomyelin. The major fatty acids were palmitic and oleic acids, but polyunsaturated fatty acids were also present in substantial amounts. The results suggest that significant de novo synthesis of lipids does not occur until after hatching.

scholarly journals Isomeric lipid signatures reveal compartmentalised fatty acid metabolism in cancer

2021 ◽  
Author(s):  
Reuben S. E. Young ◽  
Andrew P Bowman ◽  
Kaylyn Davis Tousignant ◽  
Berwyck L.J. Poad ◽  
Jennifer H Gunter ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Structural Changes ◽  
Acid Metabolism ◽  
De Novo ◽  
Net Energy ◽  
Glycerol Backbone ◽  
De Novo Synthesis ◽  
Metabolic Fate ◽  
Complex Dynamic ◽  
Cellular Energy

Cellular energy and biomass demands of cancer drive a complex dynamic between uptake of extracellular fatty acids (FA) and de novo synthesis. Given that oxidation of de novo synthesised FAs for energy would result in net-energy loss, there is an implication that FAs from these two sources must have distinct metabolic fates - however hitherto FAs were considered part of a common pool. To probe FA metabolic partitioning, cancer cells were supplemented with stable-isotope labelled FAs. Structural analysis of the resulting glycerophospholipids revealed that labelled FAs from uptake were largely incorporated to canonical (sn-)positions on the glycerol backbone. Surprisingly, labelled FA uptake disrupted canonical isomer patterns of the unlabelled lipidome and induced repartitioning of n-3 and n-6 polyunsaturated-FAs into glycerophospholipid classes. These structural changes evidence differences in the metabolic fate of FAs derived from uptake or de novo sources and demonstrate unique signalling and remodelling behaviours usually hidden to conventional lipidomics. 

INFLUENCE OF PERIODICITY OF EATING ON ADIPOSE TISSUE METABOLISM IN THE RAT

1965 ◽  
Vol 43 (6) ◽  
pp. 857-868 ◽  
Author(s):  
G. A. Leveille ◽  
R. W. Hanson
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
De Novo ◽  
Pyridine Nucleotide ◽  
Enzyme Synthesis ◽  
Pentose Phosphate ◽  
Acetate Incorporation ◽  
Initial Weight Loss ◽  
Metabolic Pattern ◽  
Carbohydrate And Lipid Metabolism

The effects of meal eating (a single 2-hour meal per day) on carbohydrate and lipid metabolism were studied in rats. Food consumption was greater in rats fed ad libitum (nibblers); however, the rate of gain was similar for both groups after an initial weight loss for the meal eaters. Isolated adipose tissue from meal eaters converted more glucose to CO2, fatty acids, nonsaponifiable lipids, and glycogen than did tissue from nibbling animals. Acetate incorporation into fatty acids was also higher in adipose tissue from meal eaters. A higher level of pentose phosphate pathway activity in adipose tissue was indicated for meal-eating rats.Refeeding for up to 2 hours after a 22-hour fast resulted in increased lipogenesis in adipose tissue from meal eaters. Total oxidized pyridine nucleotide coenzyme (NAD–NADP) levels and the rate of glucose oxidation to CO2 in rat epididymal fat pads were found to decrease during the first 30 minutes of refeeding in meal eaters. Changes noted in metabolic pattern induced by refeeding were apparently not due to de novo enzyme synthesis. The significance of the adaptive changes noted is discussed.

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