scholarly journals Hypoxia uncouples HIF gene transcription and metabolic flux in proliferating primary cells

2020 ◽  
Author(s):  
Courtney A. Copeland ◽  
Benjamin A. Olenchock ◽  
Jamey D. Young ◽  
Joseph Loscalzo ◽  
William M. Oldham
Keyword(s):  
Metabolic Flux ◽  
Hypoxia Inducible Factor ◽  
Metabolic Reprogramming ◽  
Glycolytic Flux ◽  
Primary Cells ◽  
Transcriptional Program ◽  
Environmental Stimulus ◽  
Glycolytic Gene ◽  
Bioenergetic Metabolism ◽  
Reductive Carboxylation

AbstractHypoxia is an important environmental stimulus that causes transcriptional and metabolic reprogramming in cells to facilitate their survival. Here, we performed stable isotope tracing and metabolic flux analyses of proliferating primary cells in hypoxia. Despite activation of the hypoxia-inducible factor (HIF) transcriptional program and up-regulation of glycolytic genes, glycolytic flux was decreased in hypoxic cells in our models. No evidence for increased glutaminolysis or reductive carboxylation was observed. While pharmacologic stabilization of HIF in normoxia with the prolyl hydroxylase inhibitor molidustat did increase glycolytic flux as expected, hypoxia abrogated this effect. Together, these data suggest that primary cell bioenergetic metabolism is closely coupled to cell proliferation rate and that other regulatory factors override the effects of HIF-dependent up-regulation of glycolytic gene expression on glycolytic flux.

scholarly journals Hypoxia, Metabolic Reprogramming, and Drug Resistance in Liver Cancer

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1715
Author(s):  
Macus Hao-Ran Bao ◽  
Carmen Chak-Lui Wong
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Resistance ◽  
Liver Cancer ◽  
Effective Treatment ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Metabolic Reprogramming ◽  
Combination Therapies ◽  
Low Oxygen ◽  
Treatment Regimens

Hypoxia, low oxygen (O2) level, is a hallmark of solid cancers, especially hepatocellular carcinoma (HCC), one of the most common and fatal cancers worldwide. Hypoxia contributes to drug resistance in cancer through various molecular mechanisms. In this review, we particularly focus on the roles of hypoxia-inducible factor (HIF)-mediated metabolic reprogramming in drug resistance in HCC. Combination therapies targeting hypoxia-induced metabolic enzymes to overcome drug resistance will also be summarized. Acquisition of drug resistance is the major cause of unsatisfactory clinical outcomes of existing HCC treatments. Extra efforts to identify novel mechanisms to combat refractory hypoxic HCC are warranted for the development of more effective treatment regimens for HCC patients.

scholarly journals Fine tuning the glycolytic flux ratio of EP-bifido pathway for mevalonate production by enhancing glucose-6-phosphate dehydrogenase (Zwf) and CRISPRi suppressing 6-phosphofructose kinase (PfkA) in Escherichia coli

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ying Li ◽  
He Xian ◽  
Ya Xu ◽  
Yuan Zhu ◽  
Zhijie Sun ◽  
...  
Keyword(s):  
Pentose Phosphate Pathway ◽  
Conversion Rate ◽  
Metabolic Flux ◽  
Flux Ratio ◽  
Reducing Power ◽  
Pentose Phosphate ◽  
Fine Tuning ◽  
High Yield ◽  
Glycolytic Flux ◽  
Acetyl Coa

Abstract Background Natural glycolysis encounters the decarboxylation of glucose partial oxidation product pyruvate into acetyl-CoA, where one-third of the carbon is lost at CO2. We previously constructed a carbon saving pathway, EP-bifido pathway by combining Embden-Meyerhof-Parnas Pathway, Pentose Phosphate Pathway and “bifid shunt”, to generate high yield acetyl-CoA from glucose. However, the carbon conversion rate and reducing power of this pathway was not optimal, the flux ratio of EMP pathway and pentose phosphate pathway (PPP) needs to be precisely and dynamically adjusted to improve the production of mevalonate (MVA). Result Here, we finely tuned the glycolytic flux ratio in two ways. First, we enhanced PPP flux for NADPH supply by replacing the promoter of zwf on the genome with a set of different strength promoters. Compared with the previous EP-bifido strains, the zwf-modified strains showed obvious differences in NADPH, NADH, and ATP synthesis levels. Among them, strain BP10BF accumulated 11.2 g/L of MVA after 72 h of fermentation and the molar conversion rate from glucose reached 62.2%. Second, pfkA was finely down-regulated by the clustered regularly interspaced short palindromic repeats interference (CRISPRi) system. The MVA yield of the regulated strain BiB1F was 8.53 g/L, and the conversion rate from glucose reached 68.7%. Conclusion This is the highest MVA conversion rate reported in shaken flask fermentation. The CRISPRi and promoter fine-tuning provided an effective strategy for metabolic flux redistribution in many metabolic pathways and promotes the chemicals production.

scholarly journals Mortalin/glucose-regulated protein 75 promotes the cisplatin-resistance of gastric cancer via regulating anti-oxidation/apoptosis and metabolic reprogramming

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yi Dai ◽  
Fan Li ◽  
Yuwen Jiao ◽  
Guoguang Wang ◽  
Tian Zhan ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cisplatin Resistance ◽  
Meta Analysis ◽  
Acquired Resistance ◽  
Hypoxia Inducible Factor ◽  
Metabolic Reprogramming ◽  
Platinum Resistance ◽  
Related Factor ◽  
Platinum Drug ◽  
Glucose Regulated Protein

AbstractPlatinum drug treatment is one of the most predominant chemotherapeutic strategies for patients with gastric cancer (GC). However, the therapeutic effect is less than satisfactory, largely due to the acquired resistance to platinum drugs. Therefore, a better understanding of the underlying mechanisms can greatly improve the therapeutic efficacy of GC. In this study, we aimed to investigate the chemo-resistance related functions/mechanisms and clinical significance of glucose-regulated protein 75 (GRP75) in GC. Here, our data showed that compared with SGC7901 cells, the expression of GRP75 was markedly higher in cisplatin-resistance cells (SGC7901CR). Knockdown of GRP75 abolished the maintenance of mitochondrial membrane potential (MMP) and inhibited the nuclear factor erythroid-2-related factor 2 (NRF2), phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT), hypoxia-inducible factor 1α (HIF-1α), and c-myc, which resulted in blocking the activation of their downstream targets. These processes attenuated the anti-oxidation/apoptosis abilities and altered the metabolic reprogramming in SGC7901CR cells, leading to re-sensitizing these cells to cisplatin. However, overexpression of GRP75 in SGC7901 cells caused the opposite effects. A xenografts model confirmed the abovementioned results. In GC patients receiving platinum chemotherapy and a meta-analysis, a high level of GRP75 was positively associated with aggressive characteristics and poor prognosis including but not limited to gastrointestinal cancers, and was an independent predictor for overall survival. Collectively, our study indicated that GRP75 was involved in the cisplatin-resistance of GC and that GRP75 could be a potential therapeutic target for restoring the drug response in platinum-resistance cells and a useful additive prognostic tool in guiding clinical management of GC patients.

scholarly journals Dual Specificity Kinase DYRK3 Promotes Aggressiveness of Glioblastoma by Altering Mitochondrial Morphology and Function

2021 ◽  
Vol 22 (6) ◽  
pp. 2982
Author(s):  
Kyeongmin Kim ◽  
Sungmin Lee ◽  
Hyunkoo Kang ◽  
Eunguk Shin ◽  
Hae Yu Kim ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Metabolic Flux ◽  
Mitochondrial Fission ◽  
Mammalian Target Of Rapamycin ◽  
Primary Brain Tumor ◽  
Metabolic Reprogramming ◽  
Migration And Invasion ◽  
Mitochondrial Morphology ◽  
Dual Specificity ◽  
Novel Strategy

Glioblastoma multiforme (GBM) is a malignant primary brain tumor with poor patient prognosis. Although the standard treatment of GBM is surgery followed by chemotherapy and radiotherapy, often a small portion of surviving tumor cells acquire therapeutic resistance and become more aggressive. Recently, altered kinase expression and activity have been shown to determine metabolic flux in tumor cells and metabolic reprogramming has emerged as a tumor progression regulatory mechanism. Here we investigated novel kinase-mediated metabolic alterations that lead to acquired GBM radioresistance and malignancy. We utilized transcriptomic analyses within a radioresistant GBM orthotopic xenograft mouse model that overexpresses the dual specificity tyrosine-phosphorylation-regulated kinase 3 (DYRK3). We find that within GBM cells, radiation exposure induces DYRK3 expression and DYRK3 regulates mammalian target of rapamycin complex 1 (mTORC1) activity through phosphorylation of proline-rich AKT1 substrate 1 (PRAS40). We also find that DYRK3 knockdown inhibits dynamin-related protein 1 (DRP1)-mediated mitochondrial fission, leading to increased oxidative phosphorylation (OXPHOS) and reduced glycolysis. Importantly, enforced DYRK3 downregulation following irradiation significantly impaired GBM cell migration and invasion. Collectively, we suggest DYRK3 suppression may be a novel strategy for preventing GBM malignancy through regulating mitochondrial metabolism.

scholarly journals NDUFA4L2 promotes glioblastoma progression, is associated with poor survival, and can be effectively targeted by apatinib

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Zheng Chen ◽  
Xiangyu Wei ◽  
Xueyi Wang ◽  
Xuan Zheng ◽  
Bowen Chang ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Hypoxia Inducible Factor ◽  
Mitochondrial Respiratory Chain ◽  
Metabolic Reprogramming ◽  
Tumor Cell Apoptosis ◽  
Survival Gene ◽  
A Subunit ◽  
Tumor Types

AbstractNADH dehydrogenase [ubiquinone] 1 alpha subcomplex, 4-like 2 (NDUFA4L2) is a subunit of Complex I of the mitochondrial respiratory chain, which is important in metabolic reprogramming and oxidative stress in multiple cancers. However, the biological role and molecular regulation of NDUFA4L2 in glioblastoma (GBM) are poorly understood. Here, we found that NDUFA4L2 was significantly upregulated in GBM; the elevated levels were correlated with reduced patient survival. Gene knockdown of NDUFA4L2 inhibited tumor cell proliferation and enhanced apoptosis, while tumor cells initiated protective mitophagy in vitro and in vivo. We used lentivirus to reduce expression levels of NDUFA4L2 protein in GBM cells exposed to mitophagy blockers, which led to a significant enhancement of tumor cell apoptosis in vitro and inhibited the development of xenografted tumors in vivo. In contrast to other tumor types, NDUFA4L2 expression in GBM may not be directly regulated by hypoxia-inducible factor (HIF)-1α, because HIF-1α inhibitors failed to inhibit NDUFA4L2 in GBM. Apatinib was able to effectively target NDUFA4L2 in GBM, presenting an alternative to the use of lentiviruses, which currently cannot be used in humans. Taken together, our data suggest the use of NDUFA4L2 as a potential therapeutic target in GBM and demonstrate a practical treatment approach.

scholarly journals β-Hydroxybutyrate Oxidation Promotes the Accumulation of Immunometabolites in Activated Microglia Cells

Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 346
Author(s):  
Adrian Benito ◽  
Nabil Hajji ◽  
Kevin O’Neill ◽  
Hector C. Keun ◽  
Nelofer Syed
Keyword(s):  
Metabolic Regulation ◽  
Marker Gene ◽  
Tca Cycle ◽  
Metabolic Reprogramming ◽  
Glycolytic Flux ◽  
Dihydroxyacetone Phosphate ◽  
Glycolytic Intermediate ◽  
Critical Set ◽  
The Tca Cycle ◽  
Bv2 Cells

Metabolic regulation of immune cells has arisen as a critical set of processes required for appropriate response to immunological signals. While our knowledge in this area has rapidly expanded in leukocytes, much less is known about the metabolic regulation of brain-resident microglia. In particular, the role of alternative nutrients to glucose remains poorly understood. Here, we use stable-isotope (13C) tracing strategies and metabolomics to characterize the oxidative metabolism of β-hydroxybutyrate (BHB) in human (HMC3) and murine (BV2) microglia cells and the interplay with glucose in resting and LPS-activated BV2 cells. We found that BHB is imported and oxidised in the TCA cycle in both cell lines with a subsequent increase in the cytosolic NADH:NAD+ ratio. In BV2 cells, stimulation with LPS upregulated the glycolytic flux, increased the cytosolic NADH:NAD+ ratio and promoted the accumulation of the glycolytic intermediate dihydroxyacetone phosphate (DHAP). The addition of BHB enhanced LPS-induced accumulation of DHAP and promoted glucose-derived lactate export. BHB also synergistically increased LPS-induced accumulation of succinate and other key immunometabolites, such as α-ketoglutarate and fumarate generated by the TCA cycle. Finally, BHB upregulated the expression of a key pro-inflammatory (M1 polarisation) marker gene, NOS2, in BV2 cells activated with LPS. In conclusion, we identify BHB as a potentially immunomodulatory metabolic substrate for microglia that promotes metabolic reprogramming during pro-inflammatory response.

scholarly journals Proinflammatory signal suppresses proliferation and shifts macrophage metabolism from Myc-dependent to HIF1α-dependent

2016 ◽  
Vol 113 (6) ◽  
pp. 1564-1569 ◽  
Author(s):  
Lingling Liu ◽  
Yun Lu ◽  
Jennifer Martinez ◽  
Yujing Bi ◽  
Gaojian Lian ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Hypoxia Inducible Factor ◽  
Transcriptional Program ◽  
Biosynthetic Activity ◽  
Environmental Signals ◽  
Inhibition Of Glycolysis ◽  
Metabolic Activities ◽  
And Shifts

As a phenotypically plastic cellular population, macrophages change their physiology in response to environmental signals. Emerging evidence suggests that macrophages are capable of tightly coordinating their metabolic programs to adjust their immunological and bioenergetic functional properties, as needed. Upon mitogenic stimulation, quiescent macrophages enter the cell cycle, increasing their bioenergetic and biosynthetic activity to meet the demands of cell growth. Proinflammatory stimulation, however, suppresses cell proliferation, while maintaining a heightened metabolic activity imposed by the production of bactericidal factors. Here, we report that the mitogenic stimulus, colony-stimulating factor 1 (CSF-1), engages a myelocytomatosis viral oncogen (Myc)-dependent transcriptional program that is responsible for cell cycle entry and the up-regulation of glucose and glutamine catabolism in bone marrow-derived macrophages (BMDMs). However, the proinflammatory stimulus, lipopolysaccharide (LPS), suppresses Myc expression and cell proliferation and engages a hypoxia-inducible factor alpha (HIF1α)-dependent transcriptional program that is responsible for heightened glycolysis. The acute deletion of Myc or HIF1α selectively impaired the CSF-1– or LPS-driven metabolic activities in BMDM, respectively. Finally, inhibition of glycolysis by 2-deoxyglucose (2-DG) or genetic deletion of HIF1α suppressed LPS-induced inflammation in vivo. Our studies indicate that a switch from a Myc-dependent to a HIF1α-dependent transcriptional program may regulate the robust bioenergetic support for an inflammatory response, while sparing Myc-dependent proliferation.

scholarly journals Cadmium-mediated lung injury is exacerbated by the persistence of classically activated macrophages

2020 ◽  
Vol 295 (46) ◽  
pp. 15754-15766 ◽  
Author(s):  
Jennifer L. Larson-Casey ◽  
Linlin Gu ◽  
Oliver Fiehn ◽  
A. Brent Carter
Keyword(s):  
Lung Injury ◽  
Respiratory Health ◽  
Metabolic Reprogramming ◽  
Metabolic Adaptation ◽  
Glycolytic Flux ◽  
Activated Macrophages ◽  
Lung Macrophages ◽  
Classically Activated Macrophages ◽  
Inflammatory Response To Injury ◽  
Classically Activated

Heavy metals released into the environment have a significant effect on respiratory health. Lung macrophages are important in mounting an inflammatory response to injury, but they are also involved in repair of injury. Macrophages develop mixed phenotypes in complex pathological conditions and polarize to a predominant phenotype depending on the duration and stage of injury and/or repair. Little is known about the reprogramming required for lung macrophages to switch between these divergent functions; therefore, understanding the mechanism(s) by which macrophages promote metabolic reprogramming to regulate lung injury is essential. Here, we show that lung macrophages polarize to a pro-inflammatory, classically activated phenotype after cadmium-mediated lung injury. Because metabolic adaptation provides energy for the diverse macrophage functions, these classically activated macrophages show metabolic reprogramming to glycolysis. RNA-Seq revealed up-regulation of glycolytic enzymes and transcription factors regulating glycolytic flux in lung macrophages from cadmium-exposed mice. Moreover, cadmium exposure promoted increased macrophage glycolytic function with enhanced extracellular acidification rate, glycolytic metabolites, and lactate excretion. These observations suggest that cadmium mediates the persistence of classically activated lung macrophages to exacerbate lung injury.

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