Tricarboxylic acid cycle dehydrogenases inhibition by naringenin: experimental and molecular modelling evidence

2020 ◽  
Vol 123 (10) ◽  
pp. 1117-1126
Author(s):  
Pauline Maciel August ◽  
Mateus Grings ◽  
Marcelo Sartori Grunwald ◽  
Geancarlo Zanatta ◽  
Vinícius Stone ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Tricarboxylic Acid ◽  
Metabolic Effects ◽  
Similar Reduction ◽  
Acid Cycle ◽  
Docking Simulations ◽  
Female Wistar Rats

AbstractThe study of polyphenols’ effects on health has been gaining attention lately. In addition to reacting with important enzymes, altering the cell metabolism, these substances can present either positive or negative metabolic alterations depending on their consumption levels. Naringenin, a citrus flavonoid, already presents diverse metabolic effects. The objective of this work was to evaluate the effect of maternal naringenin supplementation during pregnancy on the tricarboxylic acid cycle activity in offspring’s cerebellum. Adult female Wistar rats were divided into two groups: (1) vehicle (1 ml/kg by oral administration (p.o.)) or (2) naringenin (50 mg/kg p.o.). The offspring were euthanised at 7th day of life, and the cerebellum was dissected to analyse citrate synthase, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH) and malate dehydrogenase (MDH) activities. Molecular docking used SwissDock web server and FORECASTER Suite, and the proposed binding pose image was created on UCSF Chimera. Data were analysed by Student’s t test. Naringenin supplementation during pregnancy significantly inhibited IDH, α-KGDH and MDH activities in offspring’s cerebellum. A similar reduction was observed in vitro, using purified α-KGDH and MDH, subjected to pre-incubation with naringenin. Docking simulations demonstrated that naringenin possibly interacts with dehydrogenases in the substrate and cofactor binding sites, inhibiting their function. Naringenin administration during pregnancy may affect cerebellar development and must be evaluated with caution by pregnant women and their physicians.

scholarly journals Metabolism of glucose, glutamine, long-chain fatty acids and ketone bodies by murine macrophages

1986 ◽  
Vol 239 (1) ◽  
pp. 121-125 ◽  
Author(s):  
P Newsholme ◽  
R Curi ◽  
S Gordon ◽  
E A Newsholme
Keyword(s):  
Fatty Acids ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
The Body ◽  
Acid Cycle ◽  
Coa Transferase ◽  
Very High

Maximum activities of some key enzymes of metabolism were studied in elicited (inflammatory) macrophages of the mouse and lymph-node lymphocytes of the rat. The activity of hexokinase in the macrophage is very high, as high as that in any other major tissue of the body, and higher than that of phosphorylase or 6-phosphofructokinase, suggesting that glucose is a more important fuel than glycogen and that the pentose phosphate pathway is also important in these cells. The latter suggestion is supported by the high activities of both glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. However, the rate of glucose utilization by ‘resting’ macrophages incubated in vitro is less than the 10% of the activity of 6-phosphofructokinase: this suggests that the rate of glycolysis is increased dramatically during phagocytosis or increased secretory activity. The macrophages possess higher activities of citrate synthase and oxoglutarate dehydrogenase than do lymphocytes, suggesting that the tricarboxylic acid cycle may be important in energy generation in these cells. The activity of 3-oxoacid CoA-transferase is higher in the macrophage, but that of 3-hydroxybutyrate dehydrogenase is very much lower than those in the lymphocytes. The activity of carnitine palmitoyltransferase is higher in macrophages, suggesting that fatty acids as well as acetoacetate could provide acetyl-CoA as substrate for the tricarboxylic acid cycle. No detectable rate of acetoacetate or 3-hydroxybutyrate utilization was observed during incubation of resting macrophages, but that of oleate was 1.0 nmol/h per mg of protein or about 2.2% of the activity of palmitoyltransferase. The activity of glutaminase is about 4-fold higher in macrophages than in lymphocytes, which suggests that the rate of glutamine utilization could be very high. The rate of utilization of glutamine by resting incubated macrophages was similar to that reported for rat lymphocytes, but was considerably lower than the activity of glutaminase.

scholarly journals Metabolic phases during the development of granulation tissue

1967 ◽  
Vol 105 (1) ◽  
pp. 333-341 ◽  
Author(s):  
Kirsti Lampiaho ◽  
E. Kulonen
Keyword(s):  
Granulation Tissue ◽  
Collagen Synthesis ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
Short Period ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Observation Period

1. The metabolism of incubated slices of sponge-induced granulation tissue, harvested 4–90 days after the implantation, was studied with special reference to the capacity of collagen synthesis and to the energy metabolism. Data are also given on the nucleic acid contents during the observation period. Three metabolic phases were evident. 2. The viability of the slices for the synthesis of collagen was studied in various conditions. Freezing and homogenization destroyed the capacity of the tissue to incorporate proline into collagen. 3. Consumption of oxygen reached the maximum at 30–40 days. There was evidence that the pentose phosphate cycle was important, especially during the phases of the proliferation and the involution. The formation of lactic acid was maximal at about 20 days. 4. The capacity to incorporate proline into collagen hydroxyproline in vitro was limited to a relatively short period at 10–30 days. 5. The synthesis of collagen was dependent on the supply of oxygen and glucose, which latter could be replaced in the incubation medium by other monosaccharides but not by the metabolites of glucose or tricarboxylic acid-cycle intermediates.

Saccharomyces cerevisiae contains two functional citrate synthase genes

1986 ◽  
Vol 6 (6) ◽  
pp. 1936-1942
Author(s):  
K S Kim ◽  
M S Rosenkrantz ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Nuclear Gene ◽  
Tricarboxylic Acid ◽  
Yeast Genome ◽  
Gene Encoding ◽  
Acid Cycle ◽  
Nonfermentable Carbon Source

The tricarboxylic acid cycle occurs within the mitochondria of the yeast Saccharomyces cerevisiae. A nuclear gene encoding the tricarboxylic acid cycle enzyme citrate synthase has previously been isolated (M. Suissa, K. Suda, and G. Schatz, EMBO J. 3:1773-1781, 1984) and is referred to here as CIT1. We report here the isolation, by an immunological method, of a second nuclear gene encoding citrate synthase (CIT2). Disruption of both genes in the yeast genome was necessary to produce classical citrate synthase-deficient phenotypes: glutamate auxotrophy and poor growth on rich medium containing lactate, a nonfermentable carbon source. Therefore, the citrate synthase produced from either gene was sufficient for these metabolic roles. Transcription of both genes was maximally repressed in medium containing both glucose and glutamate. However, transcription of CIT1 but not of CIT2 was derepressed in medium containing a nonfermentable carbon source. The significance of the presence of two genes encoding citrate synthase in S. cerevisiae is discussed.

scholarly journals Tricarboxylic acid cycle and proton gradient in Pandoravirus massiliensis: Is it still a virus?

2020 ◽  
Author(s):  
Sarah Aherfi ◽  
Djamal Brahim Belhaouari ◽  
Lucile Pinault ◽  
Jean-Pierre Baudoin ◽  
Philippe Decloquement ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Isocitrate Dehydrogenase ◽  
Energy Production ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Proton Gradient ◽  
Giant Virus ◽  
Acid Cycle ◽  
Key Enzyme

ABSTRACTSince the discovery of Acanthamoeba polyphaga Mimivirus, the first giant virus of amoeba, the historical hallmarks defining a virus have been challenged. Giant virion sizes can reach up to 2.3 µm, making them visible by optical microscopy. They have large genomes of up to 2.5 Mb that encode proteins involved in the translation apparatus. Herein, we investigated possible energy production in Pandoravirus massiliensis, the largest of our giant virus collection. MitoTracker and TMRM mitochondrial membrane markers allowed for the detection of a membrane potential in virions that could be abolished by the use of the depolarizing agent CCCP. An attempt to identify enzymes involved in energy metabolism revealed that 8 predicted proteins of P. massiliensis exhibited low sequence identities with defined proteins involved in the universal tricarboxylic acid cycle (acetyl Co-A synthase; citrate synthase; aconitase; isocitrate dehydrogenase; α-ketoglutarate decarboxylase; succinate dehydrogenase; fumarase). All 8 viral predicted ORFs were transcribed together during viral replication, mainly at the end of the replication cycle. Two of these proteins were detected in mature viral particles by proteomics. The product of the ORF132, a predicted protein of P. massiliensis, cloned and expressed in Escherichia coli, provided a functional isocitrate dehydrogenase, a key enzyme of the tricarboxylic acid cycle, which converts isocitrate to α-ketoglutarate. We observed that membrane potential was enhanced by low concentrations of Acetyl-CoA, a regulator of the tricarboxylic acid cycle. Our findings show for the first time that energy production can occur in viruses, namely, pandoraviruses, and the involved enzymes are related to tricarboxylic acid cycle enzymes. The presence of a proton gradient in P. massiliensis coupled with the observation of genes of the tricarboxylic acid cycle make this virus a form a life for which it is legitimate to question ‘what is a virus?’.

Carbohydrate metabolism in Acanthamoeba castellanii. 1. The activity of key enzymes and [14C]-glucose metabolism

1973 ◽  
Vol 19 (9) ◽  
pp. 1131-1136 ◽  
Author(s):  
Lansing M. Prescott ◽  
Harold E. Hoyme ◽  
Darlene Crockett ◽  
Elena Hui
Keyword(s):  
Carbohydrate Metabolism ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Fumarate Hydratase ◽  
Acanthamoeba Castellanii ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
Key Enzymes ◽  
Glyceraldehydephosphate Dehydrogenase

The specific activities of a number of the key enzymes involved in carbohydrate metabolism in Acanthamoeba castellanii (Neff clone I–12) have been determined. The following Embden–Meyerhof and pentose phosphate pathway enzymes were present: glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphofructokinase, hexose diphosphatase, aldolase, glyceraldehydephosphate dehydrogenase, pyruvate kinase, and pyruvate-phosphate dikinase. The following tricarboxylic acid cycle enzymes were also found: citrate synthase, aconitase, isocitrate dehydrogenase, succinate dehydrogenase, fumarate hydratase, and malate dehydrogenase. The degradation of glucose-U-14C to 14CO2 was examined. Aerobic 14CO2 production from glucose-U-14C was 3.4-fold greater than anaerobic production. The data provide further evidence that the Embden–Meyerhof, pentose phosphate, and tricarboxylic acid cycle pathways are probably functional in A. castellanii.

scholarly journals 15 YEARS OF PARAGANGLIOMA: Metabolism and pheochromocytoma/paraganglioma

2015 ◽  
Vol 22 (4) ◽  
pp. T83-T90 ◽  
Author(s):  
Massimo Mannelli ◽  
Elena Rapizzi ◽  
Rossella Fucci ◽  
Letizia Canu ◽  
Tonino Ercolino ◽  
...  
Keyword(s):  
Reactive Oxygen Species Production ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Susceptibility Gene ◽  
Tricarboxylic Acid ◽  
Oxygen Species ◽  
Dna Hypermethylation ◽  
Subsequent Work ◽  
Acid Cycle ◽  
Species Production

The discovery ofSDHDas a pheochromocytoma/paraganglioma susceptibility gene was the prismatic event that led to all of the subsequent work highlighting the key roles played by mitochondria in the pathogenesis of these tumors and other solid cancers. Alterations in the function of tricarboxylic acid cycle enzymes can cause accumulation of intermediate substrates and subsequent changes in cell metabolism, activation of the angiogenic pathway, increased reactive oxygen species production, DNA hypermethylation, and modification of the tumor microenvironment favoring tumor growth and aggressiveness. The elucidation of these tumorigenic mechanisms should lead to novel therapeutic targets for the treatment of the most aggressive forms of pheochromocytoma/paraganglioma.

scholarly journals Up-regulation of glucose metabolism in Kupffer cells following infusion of tumour necrosis factor

1991 ◽  
Vol 278 (2) ◽  
pp. 515-519 ◽  
Author(s):  
Z Spolarics ◽  
G J Bagby ◽  
C H Lang ◽  
J J Spitzer
Keyword(s):  
Endothelial Cells ◽  
Kupffer Cells ◽  
Tumour Necrosis ◽  
Glucose Oxidation ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Necrosis Factor

Alterations of glucose metabolism and the oxidation of glutamine and palmitate were studied, by using specifically labelled substrates, in freshly isolated Kupffer cells and hepatic endothelial cells after infusion in vivo of human recombinant tumour necrosis factor-alpha (TNF; 7.5 x 10(5) IU/30 min per kg body wt., intravenously). Cells were incubated in a medium containing 5 mM-glucose, 0.4 mM-palmitate, 1 mM-lactate and 0.5 mM-glutamine. Administration of TNF in vivo increased glucose use in Kupffer cells by 70%. Glucose oxidation in the tricarboxylic acid cycle and flux in the Embden-Meyerhof (EM) pathway were elevated by 40 and 80% respectively. Treatment in vitro with 1 microM-phorbol 12-myristate 13-acetate (PMA) resulted in a similar percentage increase in glucose use by Kupffer cells prepared from either saline- or TNF-treated rats. However, PMA increased the activity of the hexose monophosphate shunt (HMS) by 3- and 10-fold in cells isolated from saline- or TNF-infused animals respectively. A phagocyte stimulus in vitro, opsonized zymosan, increased glucose use by 30% and doubled the flux through the HMS in Kupffer cells from saline-infused animals. The activity of the HMS in response to zymosan was increased by 400% after TNF treatment. In endothelial cells, basal glucose utilization was not altered by TNF treatment. PMA increased HMS activity in endothelial cells to a similar degree after saline or TNF infusion. Zymosan, however, increased HMS activity only in endothelial cells from TNF-treated rats. Oxidation of palmitate or glutamine was not affected by TNF treatment either under basal conditions or after challenge in vitro. Our data indicate that, after phagocytosis in vitro or protein kinase C activation, glucose use and flux through the HMS increase in Kupffer cells. This is accompanied by increased glycolytic flux, with no changes in glucose oxidation in the tricarboxylic acid cycle. After TNF exposure, followed by a secondary stimulus, the enhanced glucose use by Kupffer cells is primarily channelled through the HMS pathway. These data suggest that the increased glucose use in vivo by Kupffer cells found after immune-stimulated conditions may subserve primarily the increased need for NADPH and HMS intermediates.

Influence of some cinnamic acid derivatives on changes of the tricarboxylic acid cycle enzymes activity in rats under brain ischemia conditions

2020 ◽  
Vol 20 (2) ◽  
pp. 27-32
Author(s):  
Andrey V. Voronkov ◽  
Dmitry I. Pozdnyakov ◽  
Similla L. Adjiahmetova ◽  
Nadezhda M. Chervonnaya ◽  
Victoria M. Rukovitsina ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Cinnamic Acid ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Reference Drug ◽  
Cinnamic Acid Derivatives ◽  
Acid Cycle ◽  
Activity Of Enzymes ◽  
Ferulic Acids

The aim of the study was to assess the effect of certain derivatives of cinnamic acids on changes of the tricarboxylic acid cycle enzymes activity under experimental cerebral ischemia. Materials and methods. Brain ischemia was modeled by irreversible right-sided coagulation of the middle cerebral artery. Test compounds: 4-hydroxy-3,5-ditretbutyl cinnamic acid, coumaric, coffee, synapic, cinnamic, 4-hydroxycinnamic and ferulic acids, as well as a reference drug succinic acid was administered at a dose of 100 mg / kg per os for 3 days after the reproduction of ischemia. Then, changes in the activity of aconitase, citrate synthase, and -ketoglutarate dehydrogenase were evaluated in the supernatant of the brain. Results. The use of all the studied compounds and the reference drug helped to restore the activity of enzymes of the tricarboxylic acid cycle. The most pronounced results were obtained when animals were treated by 4-hydroxy-3,5-ditretbutyl cinnamic acid, against the background of which the activity of citrate synthase was higher than in animals treated by succinic, coumaric, coffee, synapic and ferulic acids by 1.53 (p 0.05), 1.41 (p 0.05), 1.4 (p 0.05), 1.46 (p 0.05) and 1.41 (p 0.05) times, respectively. Also, with the administration of 4-hydroxy-3,5-ditretbutyl cinnamic acid, the activity of aconitase was higher compared to rats that were administered with succinic, coumaric, coffee, synapic and ferulic acids by 2.47 (p 0.05), 2.49 (p 0.05), 3.44 (p 0.05), 2.59 (p 0.05) and 1.9 (p 0.05) times, respectively. Conclusion. The administration of the studied in this work cinnamic acid derivatives helps to restore the activity of citrate synthase, aconitase, and -ketoglutarate dehydrogenase in rats under conditions of cerebral ischemia. The most pronounced changes in the activity of enzymes were obtained with the iadministration of 4-hydroxy-3,5-ditretbutyl cinnamic acid.

scholarly journals IN VITRO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES AND OXIDATIVE PHOSPHORYLATION: PART I

1967 ◽  
Vol 15 (4) ◽  
pp. 195-201 ◽  
Author(s):  
C. JAMES LOVELACE ◽  
GENE W. MILLER
Keyword(s):  
Oxidative Phosphorylation ◽  
Competitive Inhibition ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Initial Increase ◽  
Acid Cycle ◽  
Oxidase System ◽  
Vitro Effect

Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Preincubation of mitochondria with fluoride did not increase inhibition of succinic oxidase. Various other tricarboxylic acid cycle substrates were used to determine their sensitivity to fluoride; only succinate oxidation was affected. A series of succinate concentrations in the presence and in the absence of fluoride showed increased activity of succinic dehydrogenase, which indicated competitive inhibition. Various concentrations of phosphate in the absence of fluoride showed that phosphate had only slight effects on the succinic 2,6-dichlorophenolindophenol reductase component of the succinic oxidase system. In the absence of phosphate, various concentrations of fluoride showed an initial increase in activity followed by a decrease in activity of succinic 2,6-dichlorophenolindophenol reductase. In the presence of phosphate, fluoride caused marked inhibition of succinic 2,6-dichlorophenolindophenol reductase. It is believed that this inhibition results from an enzyme-fluorophosphate complex which has a lower dissociation constant than that of the enzyme-substrate complex. An oxidative phosphorylation study indicated that both respiration and phosphorylation were inhibited.

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