scholarly journals Bedaquiline reprograms central metabolism to reveal glycolytic vulnerability in Mycobacterium tuberculosis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jared S. Mackenzie ◽  
Dirk A. Lamprecht ◽  
Rukaya Asmal ◽  
John H. Adamson ◽  
Khushboo Borah ◽  
...  
Keyword(s):  
Cell Death ◽  
Mycobacterium Tuberculosis ◽  
Metabolic Flux ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
Atp Production ◽  
Isotopomer Analysis ◽  
Metabolic Mechanism ◽  
Substantial Interest ◽  
Insight Into

AbstractThe approval of bedaquiline (BDQ) for the treatment of tuberculosis has generated substantial interest in inhibiting energy metabolism as a therapeutic paradigm. However, it is not known precisely how BDQ triggers cell death in Mycobacterium tuberculosis (Mtb). Using 13C isotopomer analysis, we show that BDQ-treated Mtb redirects central carbon metabolism to induce a metabolically vulnerable state susceptible to genetic disruption of glycolysis and gluconeogenesis. Metabolic flux profiles indicate that BDQ-treated Mtb is dependent on glycolysis for ATP production, operates a bifurcated TCA cycle by increasing flux through the glyoxylate shunt, and requires enzymes of the anaplerotic node and methylcitrate cycle. Targeting oxidative phosphorylation (OXPHOS) with BDQ and simultaneously inhibiting substrate level phosphorylation via genetic disruption of glycolysis leads to rapid sterilization. Our findings provide insight into the metabolic mechanism of BDQ-induced cell death and establish a paradigm for the development of combination therapies that target OXPHOS and glycolysis.

Regulation of Mitochondrial Ca2+ Uptake

2020 ◽  
Vol 83 (1) ◽  
Author(s):  
Elizabeth Murphy ◽  
Charles Steenbergen
Keyword(s):  
Cell Death ◽  
Genetic Alterations ◽  
Annual Review ◽  
Publication Date ◽  
Mitochondrial Matrix ◽  
Atp Production ◽  
The Past ◽  
Specific Manner ◽  
Insight Into ◽  
Disease Specific

Mitochondria are responsible for ATP production but are also known as regulators of cell death, and mitochondrial matrix Ca2+ is a key modulator of both ATP production and cell death. Although mitochondrial Ca2+ uptake and efflux have been studied for over 50 years, it is only in the past decade that the proteins responsible for mitochondrial Ca2+ uptake and efflux have been identified. The identification of the mitochondrial Ca2+ uniporter (MCU) led to an explosion of studies identifying regulators of the MCU. The levels of these regulators vary in a tissue- and disease-specific manner, providing new insight into how mitochondrial Ca2+ is regulated. This review focuses on the proteins responsible for mitochondrial transport and what we have learned from mouse studies with genetic alterations in these proteins. Expected final online publication date for the Annual Review of Physiology, Volume 83 is February 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Oxygen Regulates Human Pluripotent Stem Cell Metabolic Flux

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Jarmon G. Lees ◽  
Timothy S. Cliff ◽  
Amanda Gammilonghi ◽  
James G. Ryall ◽  
Stephen Dalton ◽  
...  
Keyword(s):  
Cell Fate ◽  
Metabolic Flux ◽  
Tca Cycle ◽  
Antioxidant Response ◽  
Open Chromatin ◽  
Rna Seq ◽  
Atp Production ◽  
The Tca Cycle ◽  
Demethylase Activity ◽  
The Impact

Metabolism has been shown to alter cell fate in human pluripotent stem cells (hPSC). However, current understanding is almost exclusively based on work performed at 20% oxygen (air), with very few studies reporting on hPSC at physiological oxygen (5%). In this study, we integrated metabolic, transcriptomic, and epigenetic data to elucidate the impact of oxygen on hPSC. Using 13C-glucose labeling, we show that 5% oxygen increased the intracellular levels of glycolytic intermediates, glycogen, and the antioxidant response in hPSC. In contrast, 20% oxygen increased metabolite flux through the TCA cycle, activity of mitochondria, and ATP production. Acetylation of H3K9 and H3K27 was elevated at 5% oxygen while H3K27 trimethylation was decreased, conforming to a more open chromatin structure. RNA-seq analysis of 5% oxygen hPSC also indicated increases in glycolysis, lysine demethylases, and glucose-derived carbon metabolism, while increased methyltransferase and cell cycle activity was indicated at 20% oxygen. Our findings show that oxygen drives metabolite flux and specifies carbon fate in hPSC and, although the mechanism remains to be elucidated, oxygen was shown to alter methyltransferase and demethylase activity and the global epigenetic landscape.

scholarly journals Amino acid and nucleotide metabolism shape the selection of trophic levels in animals

2021 ◽  
Author(s):  
Rosemary Yu ◽  
Hao Wang ◽  
Jens Nielsen
Keyword(s):  
Lipid Metabolism ◽  
Amino Acid ◽  
Metabolic Networks ◽  
Metabolic Flux ◽  
Central Carbon Metabolism ◽  
Nucleotide Metabolism ◽  
Trophic Levels ◽  
Atp Production ◽  
Species Specific ◽  
Selection Of

What an animal eats determines its trophic level (TL) in the food web. The diet of high-TL animals is thought to contain more energy because it contains higher levels of lipids. This however has not been systematically examined in the context of comprehensive metabolic networks of different animals. Here, we reconstruct species-specific genome-scale metabolic models (GEMs) of 32 animals, and calculate the maximum ATP production per unit of food for each animal. Surprisingly, we find that ATP production is closely associated with metabolic flux through central carbon metabolism and amino acid metabolism, while correlation with lipid metabolism is low. Further, metabolism of specific amino acids and nucleotides underlie maximum ATP production from food. Our analyses indicate that amino acid and nucleotide metabolism, rather than lipid metabolism, are major contributors to the selection of animal trophic levels, demonstrating that species-level metabolic flux plays key roles in trophic interactions and evolution.

scholarly journals Curcumae Radix Extract Reduces Beta-Amyloid (Αβ) and Tau Protein Through Increased Mitochondrial Respiration

2021 ◽  
Author(s):  
Seong lae Jo ◽  
Hyun Yang ◽  
Jun H. Heo ◽  
Sang R. Lee ◽  
Hye Won Lee ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Energy Metabolism ◽  
Neurodegenerative Diseases ◽  
Mitochondrial Respiration ◽  
Metabolic Flux ◽  
Tca Cycle ◽  
Basal Respiration ◽  
Atp Production ◽  
Inflammatory Conditions ◽  
Brain Tumor Cells

Abstract Background: Neurodegenerative diseases are increasingly being studied owing to the increasing proportion of the aging population. Several potential compounds have been studied to prevent neurodegenerative diseases, one of which is Curcumae Radix that is known to be beneficial for inflammatory conditions, metabolic syndrome, and various types of pain. However, it is not well studied and its influence on energy metabolism in neurodegenerative diseases is unclear. We focused on the relationship between neurodegenerative diseases and energy metabolism through Curcumae Radix extract in an animal model. Methods: Mice were treated with Curcumae Radix extract for 5 weeks orally 5 times in a week (50 mg/kg body weight). Murine delayed brain tumor (DBT) cells were supplemented with Curcumae Radix extract. We monitored the neurodegenerative makers and metabolic indicators using Western blotting and qRT-PCR and then assessed the cellular glycolysis and mitochondrial respiration through metabolic flux assay.Results: Low expression levels of Alzheimer’s disease-related markers were observed after treatment with Curcumae Radix extract. It was determined through the pAMPK/AMPK ratio that the ATP state was sufficient in the cerebrum and brain tumor cells. With this, an increase in glycolysis would be expected as glucose is the main energy source of the brain. However, glycolysis-related genes and the extracellular acidification rate showed that glycolysis decreased. Despite this, basal respiration and ATP production through mitochondrial respiration and increased TCA cycle and OXPHOS-related genes were observed in the Curcumae Radix group. Conclusions: In neurodegenerative diseases involving mitochondrial dysfunction, Curcumae Radix may act as a metabolic modulator of brain health to treat and prevent these diseases.

scholarly journals Quantitative analysis of the physiological contributions of glucose to the TCA cycle

2019 ◽  
Author(s):  
Shiyu Liu ◽  
Ziwei Dai ◽  
Daniel E. Cooper ◽  
David G. Kirsch ◽  
Jason W. Locasale
Keyword(s):  
Quantitative Analysis ◽  
Metabolic Flux ◽  
Isotope Labeling ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
Flux Analysis ◽  
Experimental Conditions ◽  
The Tca Cycle ◽  
Metabolic Physiology

ABSTRACTThe carbon source for catabolism in vivo is a fundamental question in metabolic physiology. Limited by data and rigorous mathematical analysis, controversy exists over the nutritional sources for carbon in the tricarboxylic acid (TCA) cycle under physiological settings. Using isotope-labeling data in vivo across several experimental conditions, we construct multiple models of central carbon metabolism and develop methods based on metabolic flux analysis (MFA) to solve for the preferences of glucose, lactate, and other nutrients used in the TCA cycle across many tissues. We show that in nearly all circumstances, glucose contributes more than lactate as a nutrient source for the TCA cycle. This conclusion is verified in different animal strains from different studies, different administrations of 13C glucose, and is extended to multiple tissue types. Thus, this quantitative analysis of organismal metabolism defines the relative contributions of nutrient fluxes in physiology, provides a resource for analysis of in vivo isotope tracing data, and concludes that glucose is the major nutrient used for catabolism in mammals.

scholarly journals Methionine Supplementation Affects Metabolism and Reduces Tumor Aggressiveness in Liver Cancer Cells

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2491
Author(s):  
Farida Tripodi ◽  
Beatrice Badone ◽  
Marta Vescovi ◽  
Riccardo Milanesi ◽  
Simona Nonnis ◽  
...  
Keyword(s):  
Cell Growth ◽  
Liver Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
Main Role ◽  
Atp Production ◽  
Liver Cancer Cells ◽  
Methionine Supplementation

Liver cancer is one of the most common cancer worldwide with a high mortality. Methionine is an essential amino acid required for normal development and cell growth, is mainly metabolized in the liver, and its role as an anti-cancer supplement is still controversial. Here, we evaluate the effects of methionine supplementation in liver cancer cells. An integrative proteomic and metabolomic analysis indicates a rewiring of the central carbon metabolism, with an upregulation of the tricarboxylic acid (TCA) cycle and mitochondrial adenosine triphosphate (ATP) production in the presence of high methionine and AMP-activated protein kinase (AMPK) inhibition. Methionine supplementation also reduces growth rate in liver cancer cells and induces the activation of both the AMPK and mTOR pathways. Interestingly, in high methionine concentration, inhibition of AMPK strongly impairs cell growth, cell migration, and colony formation, indicating the main role of AMPK in the control of liver cancer phenotypes. Therefore, regulation of methionine in the diet combined with AMPK inhibition could reduce liver cancer progression.

scholarly journals Metabolic Flux Ratio Analysis of Genetic and Environmental Modulations of Escherichia coli Central Carbon Metabolism

1999 ◽  
Vol 181 (21) ◽  
pp. 6679-6688 ◽  
Author(s):  
Uwe Sauer ◽  
Daniel R. Lasko ◽  
Jocelyne Fiaux ◽  
Michel Hochuli ◽  
Ralf Glaser ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Carbon Metabolism ◽  
Metabolic Flux ◽  
Flux Ratio ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
E Coli ◽  
Chemostat Cultures ◽  
Central Carbon ◽  
Pep Carboxykinase

ABSTRACT The response of Escherichia coli central carbon metabolism to genetic and environmental manipulation has been studied by use of a recently developed methodology for metabolic flux ratio (METAFoR) analysis; this methodology can also directly reveal active metabolic pathways. Generation of fluxome data arrays by use of the METAFoR approach is based on two-dimensional13C-1H correlation nuclear magnetic resonance spectroscopy with fractionally labeled biomass and, in contrast to metabolic flux analysis, does not require measurements of extracellular substrate and metabolite concentrations. METAFoR analyses of E. coli strains that moderately overexpress phosphofructokinase, pyruvate kinase, pyruvate decarboxylase, or alcohol dehydrogenase revealed that only a few flux ratios change in concert with the overexpression of these enzymes. Disruption of both pyruvate kinase isoenzymes resulted in altered flux ratios for reactions connecting the phosphoenolpyruvate (PEP) and pyruvate pools but did not significantly alter central metabolism. These data indicate remarkable robustness and rigidity in central carbon metabolism in the presence of genetic variation. More significant physiological changes and flux ratio differences were seen in response to altered environmental conditions. For example, in ammonia-limited chemostat cultures, compared to glucose-limited chemostat cultures, a reduced fraction of PEP molecules was derived through at least one transketolase reaction, and there was a higher relative contribution of anaplerotic PEP carboxylation than of the tricarboxylic acid (TCA) cycle for oxaloacetate synthesis. These two parameters also showed significant variation between aerobic and anaerobic batch cultures. Finally, two reactions catalyzed by PEP carboxykinase and malic enzyme were identified by METAFoR analysis; these had previously been considered absent in E. colicells grown in glucose-containing media. Backward flux from the TCA cycle to glycolysis, as indicated by significant activity of PEP carboxykinase, was found only in glucose-limited chemostat culture, demonstrating that control of this futile cycle activity is relaxed under severe glucose limitation.

scholarly journals A comprehensive analysis of myocardial substrate preference emphasizes the need for a synchronized fluxomic/metabolomic research design

2017 ◽  
Vol 312 (6) ◽  
pp. H1215-H1223 ◽  
Author(s):  
Mukundan Ragavan ◽  
Alexander Kirpich ◽  
Xiaorong Fu ◽  
Shawn C. Burgess ◽  
Lauren M. McIntyre ◽  
...  
Keyword(s):  
Myocardial Metabolism ◽  
Ketone Bodies ◽  
Tca Cycle ◽  
Oxidative Capacity ◽  
Total Carbohydrate ◽  
Atp Production ◽  
The Tca Cycle ◽  
Isotopomer Analysis ◽  
Myocardial Substrate ◽  
Correct Estimation

The heart oxidizes fatty acids, carbohydrates, and ketone bodies inside the tricarboxylic acid (TCA) cycle to generate the reducing equivalents needed for ATP production. Competition between these substrates makes it difficult to estimate the extent of pyruvate oxidation. Previously, hyperpolarized pyruvate detected propionate-mediated activation of carbohydrate oxidation, even in the presence of acetate. In this report, the optimal concentration of propionate for the activation of glucose oxidation was measured in mouse hearts perfused in Langendorff mode. This study was performed with a more physiologically relevant perfusate than the previous work. Increasing concentrations of propionate did not cause adverse effects on myocardial metabolism, as evidenced by unchanged O2 consumption, TCA cycle flux, and developed pressures. Propionate at 1 mM was sufficient to achieve significant increases in pyruvate dehydrogenase flux (3×), and anaplerosis (6×), as measured by isotopomer analysis. These results further demonstrate the potential of propionate as an aid for the correct estimation of total carbohydrate oxidative capacity in the heart. However, liquid chromotography/mass spectroscopy-based metabolomics detected large changes (~30-fold) in malate and fumarate pool sizes. This observation leads to a key observation regarding mass balance in the TCA cycle; flux through a portion of the cycle can be drastically elevated without changing the O2 consumption.

scholarly journals Role of pyruvate in maintaining cell viability and energy production under high-glucose conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hideji Yako ◽  
Naoko Niimi ◽  
Ayako Kato ◽  
Shizuka Takaku ◽  
Yasuaki Tatsumi ◽  
...  
Keyword(s):  
Cell Death ◽  
Schwann Cells ◽  
High Glucose ◽  
Energy Production ◽  
Parp Inhibitor ◽  
Vitamin B1 ◽  
Tca Cycle ◽  
Polyol Pathway ◽  
Glycolytic Flux ◽  
Atp Production

AbstractPyruvate functions as a key molecule in energy production and as an antioxidant. The efficacy of pyruvate supplementation in diabetic retinopathy and nephropathy has been shown in animal models; however, its significance in the functional maintenance of neurons and Schwann cells under diabetic conditions remains unknown. We observed rapid and extensive cell death under high-glucose (> 10 mM) and pyruvate-starved conditions. Exposure of Schwann cells to these conditions led to a significant decrease in glycolytic flux, mitochondrial respiration and ATP production, accompanied by enhanced collateral glycolysis pathways (e.g., polyol pathway). Cell death could be prevented by supplementation with 2-oxoglutarate (a TCA cycle intermediate), benfotiamine (the vitamin B1 derivative that suppresses the collateral pathways), or the poly (ADP-ribose) polymerase (PARP) inhibitor, rucaparib. Our findings suggest that exogenous pyruvate plays a pivotal role in maintaining glycolysis–TCA cycle flux and ATP production under high-glucose conditions by suppressing PARP activity.

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