scholarly journals Succinate Dehydrogenase Loss in Familial Paraganglioma: Biochemistry, Genetics, and Epigenetics

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Yeng F. Her ◽  
L. James Maher
Keyword(s):  
Succinate Dehydrogenase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Atp Production ◽  
Metabolic Defects ◽  
Biochemical Genetic

It is counterintuitive that metabolic defects reducing ATP production can cause, rather than protect from, cancer. Yet this is precisely the case for familial paraganglioma, a form of neuroendocrine malignancy caused by loss of succinate dehydrogenase in the tricarboxylic acid cycle. Here we review biochemical, genetic, and epigenetic considerations in succinate dehydrogenase loss and present leading models and mysteries associated with this fascinating and important tumor.

Effect of Ca2+ on cardiac mitochondrial energy production is modulated by Na+ and H+ dynamics

2007 ◽  
Vol 292 (6) ◽  
pp. C2004-C2020 ◽  
Author(s):  
My-Hanh T. Nguyen ◽  
S. J. Dudycha ◽  
M. Saleet Jafri
Keyword(s):  
Energy Metabolism ◽  
Energy Production ◽  
Hydrogen Exchange ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Calcium Dynamics ◽  
Mitochondrial Energy Metabolism ◽  
Acid Cycle ◽  
Atp Production ◽  
Sodium Hydrogen

The energy production of mitochondria in heart increases during exercise. Several works have suggested that calcium acts at multiple control points to activate net ATP production in what is termed “parallel activation”. To study this, a computational model of mitochondrial energy metabolism in the heart has been developed that integrates the Dudycha-Jafri model for the tricarboxylic acid cycle with the Magnus-Keizer model for mitochondrial energy metabolism and calcium dynamics. The model improves upon the previous formulation by including an updated formulation for calcium dynamics, and new descriptions of sodium, hydrogen, phosphate, and ATP balance. To this end, it incorporates new formulations for the calcium uniporter, sodium-calcium exchange, sodium-hydrogen exchange, the F1F0-ATPase, and potassium-hydrogen exchange. The model simulates a wide range of experimental data, including steady-state and simulated pacing protocols. The model suggests that calcium is a potent activator of net ATP production and that as pacing increases energy production due to calcium goes up almost linearly. Furthermore, it suggests that during an extramitochondrial calcium transient, calcium entry and extrusion cause a transient depolarization that serve to increase NADH production by the tricarboxylic acid cycle and NADH consumption by the respiration driven proton pumps. The model suggests that activation of the F1F0-ATPase by calcium is essential to increase ATP production. In mitochondria very close to the release sites, the depolarization is more severe causing a temporary loss of ATP production. However, due to the short duration of the depolarization the net ATP production is also increased.

scholarly journals The localization of enzymes of intermediary metabolism in Astasia and Euglena

1973 ◽  
Vol 134 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Nicole Bégin-Heick
Keyword(s):  
Succinate Dehydrogenase ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Intracellular Localization ◽  
Tricarboxylic Acid ◽  
Malate Synthase ◽  
Particulate Fraction ◽  
Acid Cycle ◽  
The Glyoxylate Cycle

Results are presented on the intracellular localization of some of the enzymes of gluconeogenesis, of the tricarboxylic acid cycle and of related enzymes in Astasia and Euglena grown with various substrates. The results indicate the particulate nature of at least part of the malate synthase of Astasia and of part of the malate synthase and isocitrate lyase in Euglena. However, the presence of glyoxysomes (microbodies) in Astasia and Euglena is still open to question, since it has not, so far, been possible to separate the enzymes of the glyoxylate cycle from succinate dehydrogenase in the particulate fraction.

scholarly journals Tricarboxylic acid-cycle and related enzymes in restricted facultative methylotrophs

1975 ◽  
Vol 148 (3) ◽  
pp. 505-511 ◽  
Author(s):  
J Colby ◽  
L J Zatman
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Isocitrate Dehydrogenase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Methylotrophic Bacteria ◽  
Acid Cycle ◽  
Oxoglutarate Dehydrogenase ◽  
Specific Activities ◽  
Succinyl Coa Synthetase

The isolation is described of pure cultures of three non-methane-utilizing methylotrophic bacteria which, together with the previously described Bacillus PM6, have a very limited range of growth substrates; these organisms are designated “restricted facultative’ methylotrophs. Two of these isolates, W6A and W3A1, grow only on glucose out of 50 non-C1 compounds tested, whereas the third isolate S2A1 and Bacillus PM6 grow on betaine, glucose, gluconate, alanine, glutamate, citrate and nutrient agar, but not on any of a further 56 non-C1 compounds. Crude sonic extracts of trimethylamine-grown and glucose-grown W6A and W3A1 isolates, and of trimethylamine-grown C2A1 (an obligate methylotroph) contain (i) no detectable 2-oxogltarate dehydrogenase activity, (ii) very low or zero specific activities of succinate dehydrogenase and succinyl-CoA synthetase and (iii) NAD+-dependent isocitrate dehydrogenase activity. Extracts of trimethylamine-grown PM6 and S2A1 methylotrophs have (i) very low 2-oxoglutarate dehydrogenase specific activities, (ii) comparatively high specific activities of succinate dehydrogenase, malate dehydrogenase and succinyl-CoA synthetase and (iii) NADP+-dependent isocitrate dehydrogenase activity but no NAD+-dependent isocitrate dehydrogenase activity. The activities of most of these enzymes are increased during growth on glucose, alanine, glutamate or citrate, but only very low 2-oxoglutarate dehydrogenase activities are present under all growth conditions. The restricted facultative methylotrophs grow on certain non-C1 compounds in the absence of 2-oxoglutarate dehydrogenase and, in some cases, of other enzymes of the tricarboxylic acid cycle; these lesions cannot therefore be the sole cause of obligate methylotrophy.

Tricarboxylic Acid Cycle Enzymes of the Ectomycorrhizal Basidiomycete, Suillus bovinus

2001 ◽  
Vol 56 (5-6) ◽  
pp. 334-342 ◽  
Author(s):  
Norbert Grotjohann ◽  
Yi Huangb ◽  
Wolfgang Kowallik
Keyword(s):  
Succinate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Technical Problems ◽  
Acid Cycle ◽  
Suillus Bovinus ◽  
Cell Extracts

In crude cell extracts of the ectomycorrhizal fungus, Suillus bovinus, activities of citrate synthase, aconitase, isocitrate dehydrogenase, succinate dehydrogenase, fumarase, and malate dehydrogenase have been proved and analyzed. Citrate synthase exhibited high affinities for both its substrates: oxaloacetate (Km = 0.018 mᴍ) and acetyl-CoA (Km = 0.014 mᴍ) . Aconitase showed better affinity for isocitrate (Km = 0.62 mᴍ) than for citrate (Km = 3.20 mᴍ) . Analysis of isocitrate dehydrogenase revealed only small maximum activity (60 nmol x mg protein-1 x min -1), the enzyme being exclusively NADP+-dependent. Using the artificial electron acceptor dichlorophenol indophenol, activity and substrate affinity of succinate dehydrogenase were rather poor. Fumarase proved Fe2+-independent. Its affinity for malate was found higher ( Km = 1.19 mᴍ) than that for fumarate ( Km = 2.09 mᴍ) . High total activity of malate dehydrogenase could be separated by native PAGE into a slowly running species of (mainly) cytosolic (about 80%) and a faster running species of (mainly) mitochondrial origin. Affinities for oxaloacetate of the two enzyme species were found identical within limits of significance (Km = 0.24 mᴍ and 0.22 mᴍ) . The assumed cytosolic enzyme exhibited affinity for malate (Km = 5.77 mᴍ) more than one order of magnitude lower than that for oxaloacetate. FPLC on superose 12 revealed only one activity band at a molecular mass of 100 ± 15 kDa. Activities of 2-oxoglutarate dehydrogenase and of succinyl-CoA synthetase could not be found. Technical problems in their detection, but also existence of an incomplete tricarboxylic acid cycle are considered. Metabolite affinities, maximum activities and pʜ-dependences of fumarase and of malate dehydrogenase allow the assumption of a reductive instead of oxidative function of these enzymes in vivo.

Tricarboxylic acid cycle dysfunction as a cause of human diseases and tumor formation

2006 ◽  
Vol 291 (6) ◽  
pp. C1114-C1120 ◽  
Author(s):  
Jean-Jacques Brière ◽  
Judith Favier ◽  
Anne-Paule Gimenez-Roqueplo ◽  
Pierre Rustin
Keyword(s):  
Succinate Dehydrogenase ◽  
Clinical Features ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Tumor Formation ◽  
Human Diseases ◽  
Acid Cycle ◽  
Cycle Enzyme

A renewed interest in tricarboxylic acid cycle enzymopathies has resulted from the report that, in addition to devastating encephalopathies, these can result in various types of tumors in human. We first review the major features of the cycle that may underlie this surprising variety of clinical features. After discussing the rare cases of encephalopathies associated with specific deficiencies of some of the tricarboxylic acid cycle enzyme, we finally examine the mechanism possibly causing tumor/cancer formation in the cases of mutations affecting fumarase or succinate dehydrogenase genes.

scholarly journals Effects of sevoflurane anesthesia and abdominal surgery on the systemic metabolome: a prospective observational study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yiyong Wei ◽  
Donghang Zhang ◽  
Jin Liu ◽  
Mengchan Ou ◽  
Peng Liang ◽  
...  
Keyword(s):  
Abdominal Surgery ◽  
General Anesthesia ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Metabolic Changes ◽  
Sevoflurane Anesthesia ◽  
Glutamate Metabolism ◽  
Acid Cycle ◽  
Link Type ◽  
The Mean

Abstract Background Metabolic status can be impacted by general anesthesia and surgery. However, the exact effects of general anesthesia and surgery on systemic metabolome remain unclear, which might contribute to postoperative outcomes. Methods Five hundred patients who underwent abdominal surgery were included. General anesthesia was mainly maintained with sevoflurane. The end-tidal sevoflurane concentration (ETsevo) was adjusted to maintain BIS (Bispectral index) value between 40 and 60. The mean ETsevo from 20 min after endotracheal intubation to 2 h after the beginning of surgery was calculated for each patient. The patients were further divided into low ETsevo group (mean − SD) and high ETsevo group (mean + SD) to investigate the possible metabolic changes relevant to the amount of sevoflurane exposure. Results The mean ETsevo of the 500 patients was 1.60% ± 0.34%. Patients with low ETsevo (n = 55) and high ETsevo (n = 59) were selected for metabolomic analysis (1.06% ± 0.13% vs. 2.17% ± 0.16%, P < 0.001). Sevoflurane and abdominal surgery disturbed the tricarboxylic acid cycle as identified by increased citrate and cis-aconitate levels and impacted glycometabolism as identified by increased sucrose and D-glucose levels in these 114 patients. Glutamate metabolism was also impacted by sevoflurane and abdominal surgery in all the patients. In the patients with high ETsevo, levels of L-glutamine, pyroglutamic acid, sphinganine and L-selenocysteine after sevoflurane anesthesia and abdominal surgery were significantly higher than those of the patients with low ETsevo, suggesting that these metabolic changes might be relevant to the amount of sevoflurane exposure. Conclusions Sevoflurane anesthesia and abdominal surgery can impact principal metabolic pathways in clinical patients including tricarboxylic acid cycle, glycometabolism and glutamate metabolism. This study may provide a resource data for future studies about metabolism relevant to general anaesthesia and surgeries. Trial registration www.chictr.org.cn. identifier: ChiCTR1800014327.

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