scholarly journals Distinct profiles of human embryonic stem cell metabolism and mitochondria identified by oxygen

Reproduction ◽  
2015 ◽  
Vol 150 (4) ◽  
pp. 367-382 ◽  
Author(s):  
Jarmon G Lees ◽  
Joy Rathjen ◽  
John R Sheedy ◽  
David K Gardner ◽  
Alexandra J Harvey
Keyword(s):  
Amino Acid ◽  
Mitochondrial Function ◽  
Cell Function ◽  
Atmospheric Oxygen ◽  
Cell Metabolism ◽  
Embryonic Stem ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Mitochondrial Activity ◽  
Hes Cells

Oxygen is a powerful regulator of cell function and embryonic development. It has previously been determined that oxygen regulates human embryonic stem (hES) cell glycolytic and amino acid metabolism, but the effects on mitochondria are as yet unknown. Two hES cell lines (MEL1, MEL2) were analyzed to determine the role of 5% (physiological) and 20% (atmospheric) oxygen in regulating mitochondrial activity. In response to extended physiological oxygen culture, MEL2 hES cells displayed reduced mtDNA content, mitochondrial mass and expression of metabolic genesTFAM,NRF1,PPARaandMT-ND4. Furthermore, MEL2 hES cell glucose consumption, lactate production and amino acid turnover were elevated under physiological oxygen. In stark contrast, MEL1 hES cell amino acid and carbohydrate use and mitochondrial function were relatively unaltered in response to oxygen. Furthermore, differentiation kinetics were delayed in the MEL1 hES cell line following BMP4 treatment. Here we report the first incidence of metabolic dysfunction in a hES cell population, defined as a failure to respond to oxygen concentration through the modulation of metabolism, demonstrating that hES cells can be perturbed during culture despite exhibiting the defining characteristics of pluripotent cells. Collectively, these data reveal a central role for oxygen in the regulation of hES cell metabolism and mitochondrial function, whereby physiological oxygen promotes glucose flux and suppresses mitochondrial biogenesis and gene expression.

scholarly journals Response of C2C12 Myoblasts to Hypoxia: The Relative Roles of Glucose and Oxygen in Adaptive Cellular Metabolism

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Li ◽  
Zhen-Fu Hu ◽  
Bin Chen ◽  
Guo-Xin Ni
Keyword(s):  
Oxygen Consumption ◽  
Glucose Concentration ◽  
Cellular Response ◽  
Cell Function ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Cellular Metabolism ◽  
Glucose Consumption ◽  
C2c12 Cells ◽  
Low Oxygen

Background. Oxygen and glucose are two important nutrients for mammalian cell function. In this study, the effect of glucose and oxygen concentrations on C2C12 cellular metabolism was characterized with an emphasis on detecting whether cells show oxygen conformance (OC) in response to hypoxia.Methods. After C2C12 cells being cultured in the levels of glucose at 0.6 mM (LG), 5.6 mM (MG), or 23.3 mM(HG) under normoxic or hypoxic (1% oxygen) condition, cellular oxygen consumption, glucose consumption, lactate production, and metabolic status were determined. Short-term oxygen consumption was measured with a novel oxygen biosensor technique. Longer-term measurements were performed with standard glucose, lactate, and cell metabolism assays.Results. It was found that oxygen depletion in normoxia is dependent on the glucose concentration in the medium. Cellular glucose uptake and lactate production increased significantly in hypoxia than those in normoxia. In hypoxia the cellular response to the level of glucose was different to that in normoxia. The metabolic activities decreased while glucose concentration increased in normoxia, while in hypoxia, metabolic activity was reduced in LG and MG, but unchanged in HG condition. The OC phenomenon was not observed in the present study.Conclusions. Our findings suggested that a combination of low oxygen and low glucose damages the viability of C2C12 cells more seriously than low oxygen alone. In addition, when there is sufficient glucose, C2C12 cells will respond to hypoxia by upregulating anaerobic respiration, as shown by lactate production.

scholarly journals Metabolic Signatures of Cryptosporidium parvum-Infected HCT-8 Cells and Impact of Selected Metabolic Inhibitors on C. parvum Infection under Physioxia and Hyperoxia

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Juan Vélez ◽  
Zahady Velasquez ◽  
Liliana M. R. Silva ◽  
Ulrich Gärtner ◽  
Klaus Failing ◽  
...  
Keyword(s):  
Host Cell ◽  
Cryptosporidium Parvum ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Host Cells ◽  
Metabolic Inhibitors ◽  
Low Oxygen ◽  
Metabolic Signatures

Cryptosporidium parvum is an apicomplexan zoonotic parasite recognized as the second leading-cause of diarrhoea-induced mortality in children. In contrast to other apicomplexans, C.parvum has minimalistic metabolic capacities which are almost exclusively based on glycolysis. Consequently, C. parvum is highly dependent on its host cell metabolism. In vivo (within the intestine) infected epithelial host cells are typically exposed to low oxygen pressure (1–11% O2, termed physioxia). Here, we comparatively analyzed the metabolic signatures of C. parvum-infected HCT-8 cells cultured under both, hyperoxia (21% O2), representing the standard oxygen condition used in most experimental settings, and physioxia (5% O2), to be closer to the in vivo situation. The most pronounced effect of C. parvum infection on host cell metabolism was, on one side, an increase in glucose and glutamine uptake, and on the other side, an increase in lactate release. When cultured in a glutamine-deficient medium, C. parvum infection led to a massive increase in glucose consumption and lactate production. Together, these results point to the important role of both glycolysis and glutaminolysis during C. parvum intracellular replication. Referring to obtained metabolic signatures, we targeted glycolysis as well as glutaminolysis in C. parvum-infected host cells by using the inhibitors lonidamine [inhibitor of hexokinase, mitochondrial carrier protein (MCP) and monocarboxylate transporters (MCT) 1, 2, 4], galloflavin (lactate dehydrogenase inhibitor), syrosingopine (MCT1- and MCT4 inhibitor) and compound 968 (glutaminase inhibitor) under hyperoxic and physioxic conditions. In line with metabolic signatures, all inhibitors significantly reduced parasite replication under both oxygen conditions, thereby proving both energy-related metabolic pathways, glycolysis and glutaminolysis, but also lactate export mechanisms via MCTs as pivotal for C. parvum under in vivo physioxic conditions of mammals.

scholarly journals Central metabolism of functionally heterogeneous mesenchymal stromal cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mario Barilani ◽  
Roberta Palorini ◽  
Giuseppina Votta ◽  
Roberta Piras ◽  
Giuseppe Buono ◽  
...  
Keyword(s):  
Stem Cells ◽  
Oxidative Phosphorylation ◽  
Cell Fate ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Mitochondrial Activity ◽  
Central Metabolism ◽  
Mt Dna ◽  
Differentiation Potential ◽  
And Function

Abstract Metabolism and mitochondrial biology have gained a prominent role as determinants of stem cell fate and function. In the context of regenerative medicine, innovative parameters predictive of therapeutic efficacy could be drawn from the association of metabolic or mitochondrial parameters to different degrees of stemness and differentiation potentials. Herein, this possibility was addressed in human mesenchymal stromal/stem cells (hMSC) previously shown to differ in lifespan and telomere length. First, these hMSC were shown to possess significantly distinct proliferation rate, senescence status and differentiation capacity. More potential hMSC were associated to higher mitochondrial (mt) DNA copy number and lower mtDNA methylation. In addition, they showed higher expression levels of oxidative phosphorylation subunits. Consistently, they exhibited higher coupled oxygen consumption rate and lower transcription of glycolysis-related genes, glucose consumption and lactate production. All these data pointed at oxidative phosphorylation-based central metabolism as a feature of higher stemness-associated hMSC phenotypes. Consistently, reduction of mitochondrial activity by complex I and III inhibitors in higher stemness-associated hMSC triggered senescence. Finally, functionally higher stemness-associated hMSC showed metabolic plasticity when challenged by glucose or glutamine shortage, which mimic bioenergetics switches that hMSC must undergo after transplantation or during self-renewal and differentiation. Altogether, these results hint at metabolic and mitochondrial parameters that could be implemented to identify stem cells endowed with superior growth and differentiation potential.

Bioenergetics and mitochondrial transmembrane potential during differentiation of cultured osteoblasts

2000 ◽  
Vol 279 (4) ◽  
pp. C1220-C1229 ◽  
Author(s):  
Svetlana V. Komarova ◽  
Fasoil I. Ataullakhanov ◽  
Ruth K. Globus
Keyword(s):  
Transmembrane Potential ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Confocal Imaging ◽  
Metabolic Inhibitors ◽  
Mitochondrial Activity ◽  
Atp Production ◽  
Fourfold Increase ◽  
Fetal Rat ◽  
Immature Cells

To evaluate the relationship between osteoblast differentiation and bioenergetics, cultured primary osteoblasts from fetal rat calvaria were grown in medium supplemented with ascorbate to induce differentiation. Before ascorbate treatment, the rate of glucose consumption was 320 nmol · h−1· 106cells−1, respiration was 40 nmol · h−1· 106cells−1, and the ratio of lactate production to glucose consumption was ∼2, indicating that glycolysis was the main energy source for immature osteoblasts. Ascorbate treatment for 14 days led to a fourfold increase in respiration, a threefold increase in ATP production, and a fivefold increase in ATP content compared with that shown in immature cells. Confocal imaging of mitochondria stained with a transmembrane potential-sensitive vital dye showed that mature cells possessed abundant amounts of high-transmembrane-potential mitochondria, which were concentrated near the culture medium-facing surface. Acute treatment of mature osteoblasts with metabolic inhibitors showed that the rate of glycolysis rose to maintain the cellular energy supply constant. Thus progressive differentiation coincided with changes in cellular metabolism and mitochondrial activity, which are likely to play key roles in osteoblast function.

174. ATMOSPHERIC OXYGEN ALTERS THE EMBRYONIC METABOLOME AS QUANTIFIED BY CARBOHYDRATE UPTAKE AND AMINO ACID UTILISATION

2010 ◽  
Vol 22 (9) ◽  
pp. 92
Author(s):  
P. L. Wale ◽  
D. K. Gardner
Keyword(s):  
Amino Acid ◽  
Atmospheric Oxygen ◽  
Oxygen Toxicity ◽  
Glucose Consumption ◽  
Blastocyst Stage ◽  
Quadrupole Mass ◽  
F1 Hybrid ◽  
Amino Acid Utilization ◽  
Hybrid Mice ◽  
Amino Acid Utilisation

Oxygen regulates embryo development at both the cleavage and post compaction stages. In this study we investigated the effects of atmospheric oxygen during the preimplantation stages, on the post-compaction embryonic metabolome through quantification of glucose consumption and amino acid utilization. Zygotes obtained from F1 hybrid mice (C57BLxCBA) were randomly allocated to either 5 or 20% oxygen. In the first experiment, following the first 48 h of culture, embryos were cultured individually in 1 μL drops of modified G2 medium (0.5 mM glucose) and moved to fresh drops of medium every 24 h. The glucose concentration in the spent media samples, including controls containing no embryo, was determined by microfluorimetry. In the second experiment, embryos which had developed to the early blastocyst stage after 72 h were cultured for a further 24 h in groups of 10 in 2 μL drops of G2. Analysis of amino acid utilization was performed using liquid chromatography-triple quadrupole mass spectrometry. Glucose consumption by embryos cultured in 5% oxygen was significantly greater on day 4 and day 5 (4.89 ± 0.29 and 6.13 ± 0.41 pmol/embryo/h) compared to embryos cultured in 20% oxygen (2.59 ± 0.40 and 5.09 ± 0.28 pmol/embryo/h; P < 0.05). In contrast amino acid utilisation by embryos cultured in 5% oxygen was significantly less than embryos cultured in 20% oxygen (P < 0.05). The data generated will help to determine the aetiology of oxygen toxicity to the preimplantation embryo. Higher glucose utilisation by embryos in 5% oxygen is consistent with their improved development. Conversely, the increased utilisation of amino acids by blastocysts in 20% oxygen may reflect an adaptation to increased oxidative stress as a result of culture in a non-physiological oxygen concentration. This study demonstrates that atmospheric oxygen during the preimplantation period perturbs the embryonic metabolome which results in a compensatory increase in amino acid utilisation.

scholarly journals Recent Advances in Chemical Biology of Mitochondria Targeting

2021 ◽  
Vol 9 ◽  
Author(s):  
Haiwei Wang ◽  
Bin Fang ◽  
Bo Peng ◽  
Limin Wang ◽  
Yufei Xue ◽  
...  
Keyword(s):  
Cell Function ◽  
Cell Metabolism ◽  
Mitochondrial Activity ◽  
Biological Applications ◽  
Chemical Probes ◽  
Recent Advances ◽  
Selective Targeting ◽  
Pros And Cons ◽  
Mitochondria Targeting ◽  
Time Acquisition

Mitochondria are vital subcellular organelles that generate most cellular chemical energy, regulate cell metabolism and maintain cell function. Mitochondrial dysfunction is directly linked to numerous diseases including neurodegenerative disorders, diabetes, thyroid squamous disease, cancer and septicemia. Thus, the design of specific mitochondria-targeting molecules and the realization of real-time acquisition of mitochondrial activity are powerful tools in the study and treatment of mitochondria dysfunction in related diseases. Recent advances in mitochondria-targeting agents have led to several important mitochondria chemical probes that offer the opportunity for selective targeting molecules, novel biological applications and therapeutic strategies. This review details the structural and physiological functional characteristics of mitochondria, and comprehensively summarizes and classifies mitochondria-targeting agents. In addition, their pros and cons and their related chemical biological applications are discussed. Finally, the potential biomedical applications of these agents are briefly prospected.

scholarly journals Metabolic regulation of collagen gel contraction by porcine aortic valvular interstitial cells

2014 ◽  
Vol 11 (101) ◽  
pp. 20140852 ◽  
Author(s):  
Peter I. Kamel ◽  
Xin Qu ◽  
Andrew M. Geiszler ◽  
Deepak Nagrath ◽  
Romain Harmancey ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Heart Valves ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Collagen Gel ◽  
Glucose Consumption ◽  
Mechanical Stimuli ◽  
Collagen Gels ◽  
Calcific Aortic Valve Disease ◽  
Metabolic Substrates

Despite a high incidence of calcific aortic valve disease in metabolic syndrome, there is little information about the fundamental metabolism of heart valves. Cell metabolism is a first responder to chemical and mechanical stimuli, but it is unknown how such signals employed in valve tissue engineering impact valvular interstitial cell (VIC) biology and valvular disease pathogenesis. In this study porcine aortic VICs were seeded into three-dimensional collagen gels and analysed for gel contraction, lactate production and glucose consumption in response to manipulation of metabolic substrates, including glucose, galactose, pyruvate and glutamine. Cell viability was also assessed in two-dimensional culture. We found that gel contraction was sensitive to metabolic manipulation, particularly in nutrient-depleted medium. Contraction was optimal at an intermediate glucose concentration (2 g l −1 ) with less contraction with excess (4.5 g l −1 ) or reduced glucose (1 g l −1 ). Substitution with galactose delayed contraction and decreased lactate production. In low sugar concentrations, pyruvate depletion reduced contraction. Glutamine depletion reduced cell metabolism and viability. Our results suggest that nutrient depletion and manipulation of metabolic substrates impacts the viability, metabolism and contractile behaviour of VICs. Particularly, hyperglycaemic conditions can reduce VIC interaction with and remodelling of the extracellular matrix. These results begin to link VIC metabolism and macroscopic behaviour such as cell–matrix interaction.

Oxygen modulates human embryonic stem cell metabolism in the absence of changes in self-renewal

2016 ◽  
Vol 28 (4) ◽  
pp. 446 ◽  
Author(s):  
Alexandra J. Harvey ◽  
Joy Rathjen ◽  
Lijia Jackie Yu ◽  
David K. Gardner
Keyword(s):  
Stem Cell ◽  
Es Cells ◽  
Atmospheric Oxygen ◽  
Embryonic Stem ◽  
Lactate Production ◽  
Cell Physiology ◽  
Stem Cell Markers ◽  
Es Cell ◽  
Oxygen Conditions ◽  
Cells Cultured

Human embryonic stem (ES) cells are routinely cultured under atmospheric oxygen (~20%), a concentration that is known to impair embryo development in vitro and is likely to be suboptimal for maintaining human ES cells compared with physiological (~5%) oxygen conditions. Conflicting reports exist on the effect of oxygen during human ES cell culture and studies have been largely limited to characterisation of typical stem cell markers or analysis of global expression changes. This study aimed to identify physiological markers that could be used to evaluate the metabolic impact of oxygen on the MEL-2 human ES cell line after adaptation to either 5% or 20% oxygen in extended culture. ES cells cultured under atmospheric oxygen displayed decreased glucose consumption and lactate production when compared with those cultured under 5% oxygen, indicating an overall higher flux of glucose through glycolysis under physiological conditions. Higher glucose utilisation at 5% oxygen was accompanied by significantly increased expression of all glycolytic genes analysed. Analysis of amino acid turnover highlighted differences in the consumption of glutamine and threonine and in the production of proline. The expression of pluripotency and differentiation markers was, however, unaltered by oxygen and no observable difference in proliferation between cells cultured in 5% and 20% oxygen was seen. Apoptosis was elevated under 5% oxygen conditions. Collectively these data suggest that culture conditions, including oxygen concentration, can significantly alter human ES cell physiology with coordinated changes in gene expression, in the absence of detectable alterations in undifferentiated marker expression.

scholarly journals Overexpression of the malate–aspartate NADH shuttle member Aralar1 in the clonal β-cell line BRIN-BD11 enhances amino-acid-stimulated insulin secretion and cell metabolism

2009 ◽  
Vol 117 (9) ◽  
pp. 321-330 ◽  
Author(s):  
Katrin Bender ◽  
Pierre Maechler ◽  
Neville H. McClenaghan ◽  
Peter R. Flatt ◽  
Philip Newsholme
Keyword(s):  
Insulin Secretion ◽  
Amino Acid ◽  
Cell Line ◽  
Recombinant Adenovirus ◽  
Cell Metabolism ◽  
Glutamate Release ◽  
Lactate Production ◽  
Control Site ◽  
Β Cell ◽  
Insulin Secreting Cells

In the present study, we have investigated the effects of the transduction with recombinant adenovirus AdCA-Aralar1 (aspartate–glutamate carrier 1) on the metabolism, function and secretory properties of the glucose- and amino-acid-responsive clonal insulin-secreting cell line BRIN-BD11. Aralar1 overexpression increased long-term (24 h) and acute (20 min) glucose- and amino-acid-stimulated insulin secretion, cellular glucose metabolism, L-alanine and L-glutamine consumption, cellular ATP and glutamate concentrations, and stimulated glutamate release. However, cellular triacylglycerol and glycogen contents were decreased as was lactate production. These findings indicate that increased malate–aspartate shuttle activity positively shifted β-cell metabolism, thereby increasing glycolysis capacity, stimulus–secretion coupling and, ultimately, enhancing insulin secretion. We conclude that Aralar1 is a key metabolic control site in insulin-secreting cells.

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