scholarly journals Mitochondrial fusion supports increased oxidative phosphorylation during cell proliferation

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Cong-Hui Yao ◽  
Rencheng Wang ◽  
Yahui Wang ◽  
Che-Pei Kung ◽  
Jason D Weber ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Oxidative Phosphorylation ◽  
Coupling Efficiency ◽  
Glucose Consumption ◽  
Mitochondrial Fusion ◽  
Quiescent State ◽  
Ras Oncogene ◽  
Proliferating Cells ◽  
Lactate Excretion ◽  
The Warburg Effect

Proliferating cells often have increased glucose consumption and lactate excretion relative to the same cells in the quiescent state, a phenomenon known as the Warburg effect. Despite an increase in glycolysis, however, here we show that non-transformed mouse fibroblasts also increase oxidative phosphorylation (OXPHOS) by nearly two-fold and mitochondrial coupling efficiency by ~30% during proliferation. Both increases are supported by mitochondrial fusion. Impairing mitochondrial fusion by knocking down mitofusion-2 (Mfn2) was sufficient to attenuate proliferation, while overexpressing Mfn2 increased proliferation. Interestingly, impairing mitochondrial fusion decreased OXPHOS but did not deplete ATP levels. Instead, inhibition caused cells to transition from excreting aspartate to consuming it. Transforming fibroblasts with the Ras oncogene induced mitochondrial biogenesis, which further elevated OXPHOS. Notably, transformed fibroblasts continued to have elongated mitochondria and their proliferation remained sensitive to inhibition of Mfn2. Our results suggest that cell proliferation requires increased OXPHOS as supported by mitochondrial fusion.

scholarly journals O-GlcNAcylation destabilizes the active tetrameric PKM2 to promote the Warburg effect

2017 ◽  
Vol 114 (52) ◽  
pp. 13732-13737 ◽  
Author(s):  
Yang Wang ◽  
Jia Liu ◽  
Xin Jin ◽  
Dapeng Zhang ◽  
Dongxue Li ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Warburg Effect ◽  
Nuclear Translocation ◽  
Lactate Production ◽  
Human Tumor ◽  
Glucose Consumption ◽  
Metabolic Reprogramming ◽  
Proliferating Cells ◽  
The Warburg Effect

The Warburg effect, characterized by increased glucose uptake and lactate production, is a well-known universal across cancer cells and other proliferating cells. PKM2, a splice isoform of the pyruvate kinase (PK) specifically expressed in these cells, serves as a major regulator of this metabolic reprogramming with an adjustable activity subjected to numerous allosteric effectors and posttranslational modifications. Here, we have identified a posttranslational modification on PKM2, O-GlcNAcylation, which specifically targets Thr405 and Ser406, residues of the region encoded by the alternatively spliced exon 10 in cancer cells. We show that PKM2 O-GlcNAcylation is up-regulated in various types of human tumor cells and patient tumor tissues. The modification destabilized the active tetrameric PKM2, reduced PK activity, and led to nuclear translocation of PKM2. We also observed that the modification was associated with an increased glucose consumption and lactate production and enhanced level of lipid and DNA synthesis, indicating that O-GlcNAcylation promotes the Warburg effect. In vivo experiments showed that blocking PKM2 O-GlcNAcylation attenuated tumor growth. Thus, we demonstrate that O-GlcNAcylation is a regulatory mechanism for PKM2 in cancer cells and serves as a bridge between PKM2 and metabolic reprogramming typical of the Warburg effect.

scholarly journals Microeconomics of Metabolism: The Warburg Effect as Giffen Behaviour

2021 ◽  
Vol 83 (12) ◽  
Author(s):  
Jumpei F. Yamagishi ◽  
Tetsuhiro S. Hatakeyama
Keyword(s):  
Oxidative Phosphorylation ◽  
Consumer Choice ◽  
Warburg Effect ◽  
Optimization Problems ◽  
Aerobic Glycolysis ◽  
Cellular Growth ◽  
Proliferating Cells ◽  
Universal Structure ◽  
Reverse Warburg Effect ◽  
The Warburg Effect

AbstractMetabolic behaviours of proliferating cells are often explained as a consequence of rational optimization of cellular growth rate, whereas microeconomics formulates consumption behaviours as optimization problems. Here, we pushed beyond the analogy to precisely map metabolism onto the theory of consumer choice. We thereby revealed the correspondence between long-standing mysteries in both fields: the Warburg effect, a seemingly wasteful but ubiquitous strategy where cells favour aerobic glycolysis over more energetically efficient oxidative phosphorylation, and Giffen behaviour, the unexpected consumer behaviour where a good is demanded more as its price rises. We identified the minimal, universal requirements for the Warburg effect: a trade-off between oxidative phosphorylation and aerobic glycolysis and complementarity, i.e. impossibility of substitution for different metabolites. Thus, various hypotheses for the Warburg effect are integrated into an identical optimization problem with the same universal structure. Besides, the correspondence between the Warburg effect and Giffen behaviour implies that oxidative phosphorylation is counter-intuitively stimulated when its efficiency is decreased by metabolic perturbations such as drug administration or mitochondrial dysfunction; the concept of Giffen behaviour bridges the Warburg effect and the reverse Warburg effect. This highlights that the application of microeconomics to metabolism can offer new predictions and paradigms for both biology and economics.

scholarly journals Mitochondrial p32 Protein Is a Critical Regulator of Tumor Metabolism via Maintenance of Oxidative Phosphorylation

2010 ◽  
Vol 30 (6) ◽  
pp. 1303-1318 ◽  
Author(s):  
Valentina Fogal ◽  
Adam D. Richardson ◽  
Priya P. Karmali ◽  
Immo E. Scheffler ◽  
Jeffrey W. Smith ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Human Cancer ◽  
Lactate Production ◽  
Surface Protein ◽  
Glucose Consumption ◽  
Human Cancer Cells ◽  
The Warburg Effect

ABSTRACT p32/gC1qR/C1QBP/HABP1 is a mitochondrial/cell surface protein overexpressed in certain cancer cells. Here we show that knocking down p32 expression in human cancer cells strongly shifts their metabolism from oxidative phosphorylation (OXPHOS) to glycolysis. The p32 knockdown cells exhibited reduced synthesis of the mitochondrial-DNA-encoded OXPHOS polypeptides and were less tumorigenic in vivo. Expression of exogenous p32 in the knockdown cells restored the wild-type cellular phenotype and tumorigenicity. Increased glucose consumption and lactate production, known as the Warburg effect, are almost universal hallmarks of solid tumors and are thought to favor tumor growth. However, here we show that a protein regularly overexpressed in some cancers is capable of promoting OXPHOS. Our results indicate that high levels of glycolysis, in the absence of adequate OXPHOS, may not be as beneficial for tumor growth as generally thought and suggest that tumor cells use p32 to regulate the balance between OXPHOS and glycolysis.

scholarly journals Author response: Mitochondrial fusion supports increased oxidative phosphorylation during cell proliferation

2018 ◽  
Author(s):  
Cong-Hui Yao ◽  
Rencheng Wang ◽  
Yahui Wang ◽  
Che-Pei Kung ◽  
Jason D Weber ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Fusion ◽  
Author Response

scholarly journals Breast cancer growth and proliferation is suppressed by the mitochondrial targeted furazano[3,4-b]pyrazine BAM15

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Elizabeth R. M. Zunica ◽  
Christopher L. Axelrod ◽  
Eunhan Cho ◽  
Guillaume Spielmann ◽  
Gangarao Davuluri ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Oxidative Phosphorylation ◽  
Energy Production ◽  
Coupling Efficiency ◽  
Breast Cancers ◽  
Mitochondrial Uncoupling ◽  
Transcriptomic Profiling ◽  
Atp Production ◽  
Luminal B

Abstract Background Enhanced metabolic plasticity and diversification of energy production is a hallmark of highly proliferative breast cancers. This contributes to poor pharmacotherapy efficacy, recurrence, and metastases. We have previously identified a mitochondrial-targeted furazano[3,4-b]pyrazine named BAM15 that selectively reduces bioenergetic coupling efficiency and is orally available. Here, we evaluated the antineoplastic properties of uncoupling oxidative phosphorylation from ATP production in breast cancer using BAM15. Methods The anticancer effects of BAM15 were evaluated in human triple-negative MDA-MB-231 and murine luminal B, ERα-negative EO771 cells as well as in an orthotopic allograft model of highly proliferative mammary cancer in mice fed a standard or high fat diet (HFD). Untargeted transcriptomic profiling of MDA-MB-231 cells was conducted after 16-h exposure to BAM15. Additionally, oxidative phosphorylation and electron transfer capacity was determined in permeabilized cells and excised tumor homogenates after treatment with BAM15. Results BAM15 increased proton leak and over time, diminished cell proliferation, migration, and ATP production in both MDA-MB-231 and EO771 cells. Additionally, BAM15 decreased mitochondrial membrane potential, while inducing apoptosis and reactive oxygen species accumulation in MDA-MB-231 and EO771 cells. Untargeted transcriptomic profiling of MDA-MB-231 cells further revealed inhibition of signatures associated with cell survival and energy production by BAM15. In lean mice, BAM15 lowered body weight independent of food intake and slowed tumor progression compared to vehicle-treated controls. In HFD mice, BAM15 reduced tumor growth relative to vehicle and calorie-restricted weight-matched controls mediated in part by impaired cell proliferation, mitochondrial respiratory function, and ATP production. LC-MS/MS profiling of plasma and tissues from BAM15-treated animals revealed distribution of BAM15 in adipose, liver, and tumor tissue with low abundance in skeletal muscle. Conclusions Collectively, these data indicate that mitochondrial uncoupling may be an effective strategy to limit proliferation of aggressive forms of breast cancer. More broadly, these findings highlight the metabolic vulnerabilities of highly proliferative breast cancers which may be leveraged in overcoming poor responsiveness to existing therapies.

scholarly journals Death and Proliferation of Lymphocytes in Immune Response and Tumor Cells Are Controlled by pH Balance

2021 ◽  
Author(s):  
Wei-ping Zeng
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Unified Theory ◽  
Biological Processes ◽  
Proliferating Cells ◽  
Proliferation Of Lymphocytes ◽  
The Warburg Effect ◽  
Acid Treatments

Many biological processes are controlled by cell death and proliferation. Previous evidence suggests that cell proliferation and death by apoptosis are regulated by separate pathways. The present study found that cellular pH was positively correlated with proliferation but negatively with cell death. Alkaline treatments enhanced lymphocyte proliferation in response to antigen challenge in vivo and in in vitro cultures, whereas acid treatments induced cell death. Low pH was incompatible with the survival of highly proliferating cells, and the susceptibility to the acid-induced death was determined in part by the proliferative status of the lymphocytes. Likewise, alkaline treatments maintained tumor cell proliferation whereas acid treatments induced death. These data support a unified theory for the regulation of cell death and proliferation where a cellular pH balance controls both events, and the mitochondria as proton generators act as pH-stats. Thus, the Warburg effect is viewed as necessary for proliferating cells to have a high cellular pH environment to both survive and accelerate proliferation.

scholarly journals Assessment and Imaging of Intracellular Magnesium in SaOS-2 Osteosarcoma Cells and Its Role in Proliferation

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1376
Author(s):  
Concettina Cappadone ◽  
Emil Malucelli ◽  
Maddalena Zini ◽  
Giovanna Farruggia ◽  
Giovanna Picone ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Magnesium Deficiency ◽  
Acid Synthesis ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
High Concentration ◽  
Proliferating Cells ◽  
Intracellular Magnesium ◽  
In Cells

Magnesium is an essential nutrient involved in many important processes in living organisms, including protein synthesis, cellular energy production and storage, cell growth and nucleic acid synthesis. In this study, we analysed the effect of magnesium deficiency on the proliferation of SaOS-2 osteosarcoma cells. When quiescent magnesium-starved cells were induced to proliferate by serum addition, the magnesium content was 2–3 times lower in cells maintained in a medium without magnesium compared with cells growing in the presence of the ion. Magnesium depletion inhibited cell cycle progression and caused the inhibition of cell proliferation, which was associated with mTOR hypophosphorylation at Serine 2448. In order to map the intracellular magnesium distribution, an analytical approach using synchrotron-based X-ray techniques was applied. When cell growth was stimulated, magnesium was mainly localized near the plasma membrane in cells maintained in a medium without magnesium. In non-proliferating cells growing in the presence of the ion, high concentration areas inside the cell were observed. These results support the role of magnesium in the control of cell proliferation, suggesting that mTOR may represent an important target for the antiproliferative effect of magnesium. Selective control of magnesium availability could be a useful strategy for inhibiting osteosarcoma cell growth.

scholarly journals Roles of autophagy and metabolism in pancreatic cancer cell adaptation to environmental challenges

2017 ◽  
Vol 313 (5) ◽  
pp. G524-G536 ◽  
Author(s):  
Sandrina Maertin ◽  
Jason M. Elperin ◽  
Ethan Lotshaw ◽  
Matthias Sendler ◽  
Steven D. Speakman ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Cell Growth ◽  
Oxidative Phosphorylation ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Environmental Stresses ◽  
Ductal Adenocarcinoma ◽  
Cell Adaptation ◽  
Autophagy Inhibition ◽  
Dependent Mechanism

Pancreatic ductal adenocarcinoma (PDAC) displays extensive and poorly vascularized desmoplastic stromal reaction, and therefore, pancreatic cancer (PaCa) cells are confronted with nutrient deprivation and hypoxia. Here, we investigate the roles of autophagy and metabolism in PaCa cell adaptation to environmental stresses, amino acid (AA) depletion, and hypoxia. It is known that in healthy cells, basal autophagy is at a low level, but it is greatly activated by environmental stresses. By contrast, we find that in PaCa cells, basal autophagic activity is relatively high, but AA depletion and hypoxia activate autophagy only weakly or not at all, due to their failure to inhibit mechanistic target of rapamycin. Basal, but not stress-induced, autophagy is necessary for PaCa cell proliferation, and AA supply is even more critical to maintain PaCa cell growth. To gain insight into the underlying mechanisms, we analyzed the effects of autophagy inhibition and AA depletion on PaCa cell metabolism. PaCa cells display mixed oxidative/glycolytic metabolism, with oxidative phosphorylation (OXPHOS) predominant. Both autophagy inhibition and AA depletion dramatically decreased OXPHOS; furthermore, pharmacologic inhibitors of OXPHOS suppressed PaCa cell proliferation. The data indicate that the maintenance of OXPHOS is a key mechanism through which autophagy and AA supply support PaCa cell growth. We find that the expression of oncogenic activation mutation in GTPase Kras markedly promotes basal autophagy and stimulates OXPHOS through an autophagy-dependent mechanism. The results suggest that approaches aimed to suppress OXPHOS, particularly through limiting AA supply, could be beneficial in treating PDAC. NEW & NOTEWORTHY Cancer cells in the highly desmoplastic pancreatic ductal adenocarcinoma confront nutrient [i.e., amino acids (AA)] deprivation and hypoxia, but how pancreatic cancer (PaCa) cells adapt to these conditions is poorly understood. This study provides evidence that the maintenance of mitochondrial function, in particular, oxidative phosphorylation (OXPHOS), is a key mechanism that supports PaCa cell growth, both in normal conditions and under the environmental stresses. OXPHOS in PaCa cells critically depends on autophagy and AA supply. Furthermore, the oncogenic activation mutation in GTPase Kras upregulates OXPHOS through an autophagy-dependent mechanism.

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